 |
| The dead battery packs |
 |
| Left - possibly recoverable, right - reasonably good |
 |
| Recovered terminals |
Once all this is complete, I will select a few packs to keep for my PRC-349s, and the rest I will sell on at a price just enough to break even.
Monday, 8 August 2016
Getting a bit further with the PRC-349 batteries!
Finally today ive finished giving my 300 odd PRC-349 batteries their initial terminal voltage check to sort the dead from the living, whether healthy or sick.
Out of around 300 batteries, about 70 show a decent terminal voltage, with a further 50-60 or so showing between a couple of volts and around 9V, so possibly recoverable. Four proved to be good Lithium primary packs, and one a usable dry cell cassette.
Before being consigned for recycling, the dead packs are being checked for any decent, or at least usable, terminals, which im removing for replacing bad terminals on otherwise good packs. Likewise seals and decent metal shaft thumb nuts are being saved.
I will also save three or four dead batteries that have exceptionally good cases, for building eliminators.
Once all this is complete, I will select a few packs to keep for my PRC-349s, and the rest I will sell on at a price just enough to break even.
Once all this is complete, I will select a few packs to keep for my PRC-349s, and the rest I will sell on at a price just enough to break even.
CHOTA this year from Selby Abbey
This afternoon I met with the vicar of Selby Abbey, to discuss the possibility of putting on a Churches On The Air day station,
Subject to some stringent timekeeping and non-interference (audible!) due to other events on the day, we have the go ahead. It is rather short notice but fortunately CHOTA is a single band event so equipment is simple and antennas even more so.
Ive already applied to Ofcom for the Special Event License. Im hoping we will get GB0SA (Selby Abbey) if there is enough time, if not we will fall back on the club call MX0TSE.
The Abbey is a wonderful building with fantastic architecture and history, well worth a visit (its free!) and great value refreshments! Its one of my favourite places and it will be an honour to operate from there.
http://www.selbyabbey.org.uk/index.html
CHOTA this year is on Saturday 10th September 10:00 - 16:00 BST.
Subject to some stringent timekeeping and non-interference (audible!) due to other events on the day, we have the go ahead. It is rather short notice but fortunately CHOTA is a single band event so equipment is simple and antennas even more so.
Ive already applied to Ofcom for the Special Event License. Im hoping we will get GB0SA (Selby Abbey) if there is enough time, if not we will fall back on the club call MX0TSE.
The Abbey is a wonderful building with fantastic architecture and history, well worth a visit (its free!) and great value refreshments! Its one of my favourite places and it will be an honour to operate from there.
http://www.selbyabbey.org.uk/index.html
CHOTA this year is on Saturday 10th September 10:00 - 16:00 BST.
Tuesday, 2 August 2016
Clansman Manpacks for Amateur Use - Part 5b
PRC-320 HF Antennas
No mucking aboot, straight into it! For HF, were talking wire! At least, mostly...
SO, you have spent your hard earned shekles on a PRC-320, but been slightly taken in and its body only. You've collected up a battery, and a handset, now you need an antenna,
The basic starting point is the whip. This is an interlocking sectional antenna 2.4m long. However, it cannot be used directly with the radio, instead it requires an antenna gooseneck adapter. This is a hefty spring with a circlip secured hole for the whip, and a rod for the antenna socket of the radio.
Just like the one above, which incidentally im selling on ebay [eBay item number: 272308793412] for a very competitive price. This allows you to position the whip at various angles as required.
All well and good, but you wont get very far on just the whip. Thats not to say you cant make contacts - I had a QSO with a German station on just the whip on 40m from my workshop, and Bob M1BBV did rather well into the States on it on 10m. But, there are ways to make it better - Groundplanes!
The top one is the cheapest, but also a bit fiddly to use. A short wire connects to the -320's ground stud, and the four 9m long wires are unwound and laid out in a cross around the radio. The lower spool is a more up to date version and each wire is on its own little spool.
Now, you cant help but have noticed, unless your set hasnt got one, that theres a tuning chart on the radio. This tells you the settings of the built in TURF (ATU) for various antenna configurations. You will notice it gives values for the 2.4m whip, but also 5.5m and 7m verticals, end fed wires, and dipoles. Ah, dipoles, so now you understand why theres a removable coax link on the back of the rig!
Lets stick for now with the verticals. Remember that odd bit of wire with the 5.4m mast kit? Pop it on top of the mast, and thread it through the little hole in each of the guy plates. Now, look just below the antenna socket on the radio, theres a little spring terminal. Press it, and stick the pin on the end of the wire in the little hole - voila! You now have a 5.5m vertical antenna! You should, of course, be doing this with the above groundplane also attached.
So, whats the 7m vertical mentioned? Well, before putting the mast up, stick the 2.4m whip into the hole in the little tube that the wire is attached to on the top of the mast- 5.5 + 2.4 = er, about 7m!
With your PRC-320, you should also have obtained for yourself a 20m coax lead, a dipole center, and two spools of Clansman braided antenna wire. From these, come your end fed and dipole options. Notice that the wire on the spools has various colours and numbers of tie-wraps on it - these are length markers! Unwind the amount of wire needed according to the tuning chart, pass the end through the hole on the dipole center and into the terminal (or direct into the radio terminal if an end fed), pass the wire at the spool end through one of the tight slots on the spool, to stop it unravelling. Thats your antenna element. Do the same with enough of the cord to pull the wire up over whatever support your using (if that the 5.4m mast, then thread the cord through the guy plate holes and around the tie-off plate).
I wont go into all the dipole and end fed antenna variations possible, as these are all in the back of the PRC-320 user manual, which surely you have downloaded and read by now? No? well why not?
For most of the antenna systems mentioned in these posts, if you trawl back through this blog you will find example pictures. There are also 8m and 12m masts available, but those are getting a bit too unweidly to be classed as man portable!
And, really, thats about it! From this short series of posts, hopefully ive explained the basics of getting set up to use these fine green machines for amateur purposes. I dont intend any specifc posts about actually operating them though! Working that out for yourself is part of the fun! I will however, do one last post, no. 6, if you have the stomach for any more, and just mention a few of the other little bits and bobs you'll find you cant live without!
No mucking aboot, straight into it! For HF, were talking wire! At least, mostly...
SO, you have spent your hard earned shekles on a PRC-320, but been slightly taken in and its body only. You've collected up a battery, and a handset, now you need an antenna,
The basic starting point is the whip. This is an interlocking sectional antenna 2.4m long. However, it cannot be used directly with the radio, instead it requires an antenna gooseneck adapter. This is a hefty spring with a circlip secured hole for the whip, and a rod for the antenna socket of the radio.
 |
| PRC-320 Antenna Gooseneck adapter |
All well and good, but you wont get very far on just the whip. Thats not to say you cant make contacts - I had a QSO with a German station on just the whip on 40m from my workshop, and Bob M1BBV did rather well into the States on it on 10m. But, there are ways to make it better - Groundplanes!
The top one is the cheapest, but also a bit fiddly to use. A short wire connects to the -320's ground stud, and the four 9m long wires are unwound and laid out in a cross around the radio. The lower spool is a more up to date version and each wire is on its own little spool.
Now, you cant help but have noticed, unless your set hasnt got one, that theres a tuning chart on the radio. This tells you the settings of the built in TURF (ATU) for various antenna configurations. You will notice it gives values for the 2.4m whip, but also 5.5m and 7m verticals, end fed wires, and dipoles. Ah, dipoles, so now you understand why theres a removable coax link on the back of the rig!
Lets stick for now with the verticals. Remember that odd bit of wire with the 5.4m mast kit? Pop it on top of the mast, and thread it through the little hole in each of the guy plates. Now, look just below the antenna socket on the radio, theres a little spring terminal. Press it, and stick the pin on the end of the wire in the little hole - voila! You now have a 5.5m vertical antenna! You should, of course, be doing this with the above groundplane also attached.
So, whats the 7m vertical mentioned? Well, before putting the mast up, stick the 2.4m whip into the hole in the little tube that the wire is attached to on the top of the mast- 5.5 + 2.4 = er, about 7m!
With your PRC-320, you should also have obtained for yourself a 20m coax lead, a dipole center, and two spools of Clansman braided antenna wire. From these, come your end fed and dipole options. Notice that the wire on the spools has various colours and numbers of tie-wraps on it - these are length markers! Unwind the amount of wire needed according to the tuning chart, pass the end through the hole on the dipole center and into the terminal (or direct into the radio terminal if an end fed), pass the wire at the spool end through one of the tight slots on the spool, to stop it unravelling. Thats your antenna element. Do the same with enough of the cord to pull the wire up over whatever support your using (if that the 5.4m mast, then thread the cord through the guy plate holes and around the tie-off plate).
 |
| Antenna wire spool |
For most of the antenna systems mentioned in these posts, if you trawl back through this blog you will find example pictures. There are also 8m and 12m masts available, but those are getting a bit too unweidly to be classed as man portable!
And, really, thats about it! From this short series of posts, hopefully ive explained the basics of getting set up to use these fine green machines for amateur purposes. I dont intend any specifc posts about actually operating them though! Working that out for yourself is part of the fun! I will however, do one last post, no. 6, if you have the stomach for any more, and just mention a few of the other little bits and bobs you'll find you cant live without!
Clansman Manpacks for Amateur Use - Part 5a
Bear with me (grrrr!) - we're almost done!
So, so far we've talked about which of the Clansman series manpack radios are suitable for amateur use, what you'd need to get one powered, and how to actually listen and talk on it if you have one (I offer no guarentee that theres anyone listening!), so all thats left is to discuss the basics of antennas for them.
Now, as these are the man portable radios, the antennas i'll mention are also man portable. The general operational doctrine in the field was usually that, with the exception of inter-section comms, the manpack would be talking to either a vehicle mounted system, or either a fixed or field commcen (communications center) which could be a couple of 12m masts and tents, an RN ship, or something a little bigger like DHFS Forrest Moor with its huge HF log periodics. The onus often, especially for HF, being on the more capable station taking the brunt of the link.
I'll start with the PRC350, and move on 'up the chain' as it were
PRC-350 Antennas
The PRC-350 has a bayonet fitting antenna socket for what are termed 'battle whips'. There are two common types, with corresponding differences in performance. The first is a 'rubber duck' type flexible 60cm helical antenna. This has an advantage of being pretty much indestructable, but of course not a great range! More useful is the 1.2m sectional whip. More rigid, but with a sprung ball and socket mounting, this comprises four tubular sections attached with an elastic cord.
Both of these are ok if your actually carrying your PRC-350 on your back or hip. Often available for very little money, but probably of very limited use, is the 'trailing wire' antenna. This is a 1.2m long length of braided antenna wire and a bayonet connector. Its tactical use can be appreciated, but for amateur purposes its little more than a curiosity.
So those are your usual antenna options for the PRC-350. Doesnt give you much leeway for your 2W does it? But, you may have noticed your radio has a dinky mini-BNC socket on it. We'll see why shortly,
PRC-351 and -352
The higher powered PRC-351, with its thobbing 4W, also has the same bayonet fitting antenna connector as the -350, and so can use any of the above antennas. But, it also has a BNC connector. This BNC is to allow you to use it with the big brother antenna, the GSA (Ground Spike Antenna)
The GSA is a kit, available in Long or Short Rod versions, comprising a base matching unit, several antenna rods, coax lead, carry bag, and the namesake ground spike.The general idea is to fit to the base matching unit the desired number of push together antenna rods (number per frequency range is conveniently printed on the side of the base), attach this to the spike, ram the spike into the ground, and run the coax off to the radios BNC connector. In the tactical environment, this meant the antenna could be out in the open where it was effective, whilst the radio and the squaddie hid away in cover. Incidentally, if you have a short rod kit, just use double the numbers on the data plate.
The GSA antenna is essential if you have a PRC-352, as this cannot be used with the battle whips.
Have you discovered the odd 40cm coax lead that came with the kit? Yep, thats the adaptor for the mini-BNC on the PRC-350!
The GSA is not too bad an antenna, but its still rather low down. VHF likes height, so another kit is available, the EKGSA (Elevation Kit, Ground Spike Antenna). Supplied, hopefully, in its own carrying satchel, this kit comprises all you need to mount the GSA on top of the 5.4m mast (of which more later), or to hang it from a tree or other suitable support. The key to it is the set of measured coax cables and the mast mounting inductor unit. These between them provide an artificial ground for the GSA.
There is also a 'long wire' antenna system available, but this never seems to turn up intact, rather the antenna wire spools show up but not the terminating resistors or feed inductors. Other antennas you will see are the 'pineapple' which is similar to the GSA but of a wideband design. This is not by any form of clever matching system, but rather by a terminating resistor! Not great for your measly few watts. Another you might see for sale is the 'ground mounted monopole', commonly known as the washing line, for reasons that should be apparent to anyone whos ever used a rotary clothes airer! Again, probably not of any great use, but if you have the money, by all means get one.
To use the EKGSA at height, if you dont have a nice tall tree with spreading boughs, you'll need a mast. The EKGSA (and many other antennas for the HF side of things) are designed to be used with the 5.4m Fibreglass mast kit.
It is true that these can be erected, as the manual states 'by a single well trained soldier' but its far easier with two or more people! Six interlocking thick wall fibreglass tubes and two sets of three guy strings, plus five ground anchor pegs. There should also be a odd looking short tube with a wire attached, why, we shall see when we talk HF antennas.
Im going to put HF antennas in their own post, as theres more options there than with the VHF kit.
So, so far we've talked about which of the Clansman series manpack radios are suitable for amateur use, what you'd need to get one powered, and how to actually listen and talk on it if you have one (I offer no guarentee that theres anyone listening!), so all thats left is to discuss the basics of antennas for them.
Now, as these are the man portable radios, the antennas i'll mention are also man portable. The general operational doctrine in the field was usually that, with the exception of inter-section comms, the manpack would be talking to either a vehicle mounted system, or either a fixed or field commcen (communications center) which could be a couple of 12m masts and tents, an RN ship, or something a little bigger like DHFS Forrest Moor with its huge HF log periodics. The onus often, especially for HF, being on the more capable station taking the brunt of the link.
I'll start with the PRC350, and move on 'up the chain' as it were
PRC-350 Antennas
The PRC-350 has a bayonet fitting antenna socket for what are termed 'battle whips'. There are two common types, with corresponding differences in performance. The first is a 'rubber duck' type flexible 60cm helical antenna. This has an advantage of being pretty much indestructable, but of course not a great range! More useful is the 1.2m sectional whip. More rigid, but with a sprung ball and socket mounting, this comprises four tubular sections attached with an elastic cord.
 |
| 0.6m flexible battle whip |
 |
| 1.2m sectional whip |
Both of these are ok if your actually carrying your PRC-350 on your back or hip. Often available for very little money, but probably of very limited use, is the 'trailing wire' antenna. This is a 1.2m long length of braided antenna wire and a bayonet connector. Its tactical use can be appreciated, but for amateur purposes its little more than a curiosity.
 |
| Trailing wire antenna |
So those are your usual antenna options for the PRC-350. Doesnt give you much leeway for your 2W does it? But, you may have noticed your radio has a dinky mini-BNC socket on it. We'll see why shortly,
PRC-351 and -352
The higher powered PRC-351, with its thobbing 4W, also has the same bayonet fitting antenna connector as the -350, and so can use any of the above antennas. But, it also has a BNC connector. This BNC is to allow you to use it with the big brother antenna, the GSA (Ground Spike Antenna)
 |
| GSA Kit |
The GSA antenna is essential if you have a PRC-352, as this cannot be used with the battle whips.
Have you discovered the odd 40cm coax lead that came with the kit? Yep, thats the adaptor for the mini-BNC on the PRC-350!
The GSA is not too bad an antenna, but its still rather low down. VHF likes height, so another kit is available, the EKGSA (Elevation Kit, Ground Spike Antenna). Supplied, hopefully, in its own carrying satchel, this kit comprises all you need to mount the GSA on top of the 5.4m mast (of which more later), or to hang it from a tree or other suitable support. The key to it is the set of measured coax cables and the mast mounting inductor unit. These between them provide an artificial ground for the GSA.
 |
| EKGSA kit |
To use the EKGSA at height, if you dont have a nice tall tree with spreading boughs, you'll need a mast. The EKGSA (and many other antennas for the HF side of things) are designed to be used with the 5.4m Fibreglass mast kit.
 |
| 5.4m Mast Kit |
Im going to put HF antennas in their own post, as theres more options there than with the VHF kit.
Sunday, 24 July 2016
Clansman Manpacks for Amateur Use - Part 4
So you have your radio but so far cant do anything with it, not even tell if it works, because you need - audio ancillaries! We will talk about those in this post, plus a few other bits and bobs, but first, a word from our sponsors -
Army Radio Sales
PTS Norfolk
Alright, so they are not really sponsors, its not like they have given me anything to plug them on my blog (yet - you know where I am fellas ;-) ), but I ought to mention them as good suppliers of Clansman radios and spares, if only because I have quite blatantly nicked their photos for this post!
So, on to the audio!
Whichever radio you have, you will need some way to hear it and to talk on it. This is the one area where almost all Clansman equipment is the same - the audio ancillaries are all interchangeable. This is great as sometimes one type is better than another different set-up. For instance I like the standard headset for my PRC-320 if its on my back, but prefer a handset for fixed use.
Handset
The handset is probably the simplest to use, as its used just like a telephone, only theres a PTT (pressel) on the handle.
You may recall my cable-less handset - this is a 'Remote' handset, intended to be connected to the radio from a distance of up to 3km using telephone wire (properly DON-10, but at a push whatever is to hand). The PRC-351/2 can do this natively, theres a pair of terminals on it. This allows the radio to be used from a distance, ideal when the enemy DF you and mortar the position you left the radio in (not too likely for amateur use outside of Barnsley), but also as an intercom between the handset and the radio.
Headsets
sets... for yer 'ead! Probably the most common accessory you will find supplied with PRC-351s. Most will be the 'Lightweight, Infantry' type shown below on Desperate Dan
These are ok, an advantage they have is that the two earpieces are independent channels, and one of them can be popped out to make hearing whats going on around you easier. The idea of the independent channels is so that when used in an AFV the radio can be in one ear, and the commanders intercom shouting at you in the other. The radios have both audio channels in parallel, so unless you run them through the various vehicle intercom boxes, you will get the radio audio from both earpieces anyway.
Another headset style is the Armoured vehicle type below, designed to be used with a tankies helmet (not to be confused with his Bobbies Helmet!)
Neither headset is any use on its own, as they dont have an integral PTT. So you must make sure you get a Pressel cable with them -
More commonly used with the PRC-349, there is the single earpiece Throat Mic
Not too bad but you do have to strap the mic around your neck! so they are quite unpopular as a result. There is also the Single Transducer Earpiece, shown in the black and white below. Quite unusual, and seemingly issued with the PRC-319, this has an integral PTT on the top, and uses bone conduction for your voice - this means that your transmission goes out sounding the way YOU think you sound, not how others actually hear you! Expect people to not recognise your voice!
And thats most of your audio options. If you can afford one, a freestanding loudspeaker is nice to have for the PRC-320 in particular
There are also audio extension cables available that allow you to use the radios from around 10m away.
You may also find microphones on their own, with an odd three pin plug on them. You dont need one of these (even if you discover the matching socket on the headset) unless your intending to play ham radio in State 3 Romeo, which to those uninitiated into the world of NBC Warfare (Nuclear, Biological, Chemical) means wearing full chemical warfare clothing and respirator. This mic is the respirator mic - intended to fit on the speech capsule of your gas mask! No, I dont have one of these mics (although I DO have my S10 respirator!)
If you have a PRC-320 or 319, you might also like a Morse key! There are a few types available. Mine is a fully enclosed Racal thigh key (ie it straps to your leg!). The usual Clansman thigh key has a couple of adjusters on top.
So all thats left now is to discuss antennas!
Army Radio Sales
PTS Norfolk
Alright, so they are not really sponsors, its not like they have given me anything to plug them on my blog (yet - you know where I am fellas ;-) ), but I ought to mention them as good suppliers of Clansman radios and spares, if only because I have quite blatantly nicked their photos for this post!
So, on to the audio!
Whichever radio you have, you will need some way to hear it and to talk on it. This is the one area where almost all Clansman equipment is the same - the audio ancillaries are all interchangeable. This is great as sometimes one type is better than another different set-up. For instance I like the standard headset for my PRC-320 if its on my back, but prefer a handset for fixed use.
Handset
The handset is probably the simplest to use, as its used just like a telephone, only theres a PTT (pressel) on the handle.
You may recall my cable-less handset - this is a 'Remote' handset, intended to be connected to the radio from a distance of up to 3km using telephone wire (properly DON-10, but at a push whatever is to hand). The PRC-351/2 can do this natively, theres a pair of terminals on it. This allows the radio to be used from a distance, ideal when the enemy DF you and mortar the position you left the radio in (not too likely for amateur use outside of Barnsley), but also as an intercom between the handset and the radio.
Headsets
sets... for yer 'ead! Probably the most common accessory you will find supplied with PRC-351s. Most will be the 'Lightweight, Infantry' type shown below on Desperate Dan
These are ok, an advantage they have is that the two earpieces are independent channels, and one of them can be popped out to make hearing whats going on around you easier. The idea of the independent channels is so that when used in an AFV the radio can be in one ear, and the commanders intercom shouting at you in the other. The radios have both audio channels in parallel, so unless you run them through the various vehicle intercom boxes, you will get the radio audio from both earpieces anyway.
Another headset style is the Armoured vehicle type below, designed to be used with a tankies helmet (not to be confused with his Bobbies Helmet!)
Neither headset is any use on its own, as they dont have an integral PTT. So you must make sure you get a Pressel cable with them -
More commonly used with the PRC-349, there is the single earpiece Throat Mic
Not too bad but you do have to strap the mic around your neck! so they are quite unpopular as a result. There is also the Single Transducer Earpiece, shown in the black and white below. Quite unusual, and seemingly issued with the PRC-319, this has an integral PTT on the top, and uses bone conduction for your voice - this means that your transmission goes out sounding the way YOU think you sound, not how others actually hear you! Expect people to not recognise your voice!
And thats most of your audio options. If you can afford one, a freestanding loudspeaker is nice to have for the PRC-320 in particular
There are also audio extension cables available that allow you to use the radios from around 10m away.
You may also find microphones on their own, with an odd three pin plug on them. You dont need one of these (even if you discover the matching socket on the headset) unless your intending to play ham radio in State 3 Romeo, which to those uninitiated into the world of NBC Warfare (Nuclear, Biological, Chemical) means wearing full chemical warfare clothing and respirator. This mic is the respirator mic - intended to fit on the speech capsule of your gas mask! No, I dont have one of these mics (although I DO have my S10 respirator!)
If you have a PRC-320 or 319, you might also like a Morse key! There are a few types available. Mine is a fully enclosed Racal thigh key (ie it straps to your leg!). The usual Clansman thigh key has a couple of adjusters on top.
So all thats left now is to discuss antennas!
Lots of new readers?
Ive noticed in the last few days, seemingly since I started the Clansman articles, that my daily readership stats have rocketed! Now, this could of course just be the ol' bots crawling over my musings, but perhaps - and stranger things have happened! - just perhaps, its actually real people reading this?
Are you one of these real persons? You all dont say much, but I know your out there I can hear you breathing! Why not pop a comment on? Let me know what your liking about the blog.
Are you one of these real persons? You all dont say much, but I know your out there I can hear you breathing! Why not pop a comment on? Let me know what your liking about the blog.
Clansman Manpacks for Amateur Use - Part 3
Ok then, back to the basics of the Clansman series manpack radios. Firstly, a word or two about...
SURF (Selector Unit Radio Frequency)
Heres what to do if you think you need a SURF - Forget it!
The Selector Unit Radio Frequency is one of those devices which, particularly the 4W SURF for the PRC-351, you will be offered. You dont need one! In fact, it can even make your signal worse! The purpose of a SURF is to prevent adjacent channel interference or receiver blocking when two or more radios are used very close together physically - for example in a command post bunker. It is simply a preselector. If your going for the 'CES' look (Complete Equipment Specification) for a collection or re-enactment, or to equip your newly restored FFR Landrover (Fitted For Radio, not to be confused with most MoD hardware acquisitions of the last two decades - FFBNW - Fitted For But Not With) then by all means put a 4W SURF on the top of your PRC-351 (I have!) but dont use it for actual on the air operation.
SURFs are also available for the PRC-320 (only ever seen one and that was on a table at the Finningley Rally today!) and the PRC-350.
Don't confuse the SURF with the TURF - Tuning Unit Radio Frequency! TURFs are what we amateurs call ATUs! You will not see them for the usual manpack range, they are more of a VRC (Vehicle) item. But the PRC-319 has one, which is automatic. Likewise, the PRC-351/2 when used in a vehicle can be used with the TUAAM, which is a VHF automatic TURF unit (Tuning Unit Automatic Antenna Matching).
While we are on RF accessories, i'll mention the 20W amp that turns a 4W PRC-351 into ...
PRC-352 20W
The PRC-351 when used with the clip on 20W amplifier becomes designated the PRC-352. At this point, you must start using proper antennas not the battle whips. If you do use the amp, make sure you physically remove the whip, otherwise the resulting dual radiation and poor impedance match causes poor performance.
The amp clips on to the bottom of the PRC-351 where the battery was, and the battery then clips to the bottom of the amp. An 18inch long coax cable connects the two. There is a waveband select switch on the amp which must be set for the frequency in use, but thats about it.
So, if you have got yourself a Clansman radio, be it a 320 for HF, or a 350 or 351, even a 352, for VHF, your almost ready to go. But not quite. You now need a power source - a battery. But, unlike modern amateur equipment, you still cant then just turn it on and go. You need audio ancillaries!
Batteries
I wont put pictures of batteries up, as you can easily find these on the blog, and besides you have hopefully got the seller to throw one in!
Both the PRC-320 and PRC-351/2, and the PRC-319, use the standard 24V NiCd packs. These come in two current flavours - 1Ahr and 4Ahr (some variations do exist) and either plastic or alloy cases. The alloy cased batteries are easiest to strip to build modern batteries into. The 1Ahr is about half the size of the 4Ahr. There is even a primary lithium version available.
These batteries of course need a charger. The standard charger is the DCCU, but 12V fed DCCUs are hard to find and expensive. Most are 24V for vehicle use. It is much easier to charge them using a modern intelligent charger that can do all your batteries, such as the Turnigy Accucel-8 I use.
The PRC-350 uses a special and unique 15V battery. Most likely you will get a battery cassette, to take D cells. Invest in some NiMH cells for this, as using alkalines will cost a fortune. Likewise the PRC-349s use an odd 12V 600mAh pack, and if you did get one of these radios you'd most likely get a cassette with it. Incidentally ive got hundreds of these...
I'll talk about audio ancillaries in the next entry. This is quite a wide subject.
Over the past few days ive had my EKGSA antenna rigged on one of my 5.4m masts. This had to come down today, and did so shortly after the heavy showers. Luckily the showers held of for the duration of the Finningley clubs radio rally.
It was great wandering around in the sunshine deciding what junk I could get away with taking home! In the end though, I bought very little - a surface mount relay, and a Clansman Remote Handset.
You might notice that the handset has no cable... find out why in the next thrilling installment!
SURF (Selector Unit Radio Frequency)
Heres what to do if you think you need a SURF - Forget it!
The Selector Unit Radio Frequency is one of those devices which, particularly the 4W SURF for the PRC-351, you will be offered. You dont need one! In fact, it can even make your signal worse! The purpose of a SURF is to prevent adjacent channel interference or receiver blocking when two or more radios are used very close together physically - for example in a command post bunker. It is simply a preselector. If your going for the 'CES' look (Complete Equipment Specification) for a collection or re-enactment, or to equip your newly restored FFR Landrover (Fitted For Radio, not to be confused with most MoD hardware acquisitions of the last two decades - FFBNW - Fitted For But Not With) then by all means put a 4W SURF on the top of your PRC-351 (I have!) but dont use it for actual on the air operation.
 |
| 4W SURF |
 |
| PRC-350 with SURF |
SURFs are also available for the PRC-320 (only ever seen one and that was on a table at the Finningley Rally today!) and the PRC-350.
 |
| PRC-320 SURF |
While we are on RF accessories, i'll mention the 20W amp that turns a 4W PRC-351 into ...
PRC-352 20W
The PRC-351 when used with the clip on 20W amplifier becomes designated the PRC-352. At this point, you must start using proper antennas not the battle whips. If you do use the amp, make sure you physically remove the whip, otherwise the resulting dual radiation and poor impedance match causes poor performance.
 |
| 20W amplifier block |
So, if you have got yourself a Clansman radio, be it a 320 for HF, or a 350 or 351, even a 352, for VHF, your almost ready to go. But not quite. You now need a power source - a battery. But, unlike modern amateur equipment, you still cant then just turn it on and go. You need audio ancillaries!
Batteries
I wont put pictures of batteries up, as you can easily find these on the blog, and besides you have hopefully got the seller to throw one in!
Both the PRC-320 and PRC-351/2, and the PRC-319, use the standard 24V NiCd packs. These come in two current flavours - 1Ahr and 4Ahr (some variations do exist) and either plastic or alloy cases. The alloy cased batteries are easiest to strip to build modern batteries into. The 1Ahr is about half the size of the 4Ahr. There is even a primary lithium version available.
These batteries of course need a charger. The standard charger is the DCCU, but 12V fed DCCUs are hard to find and expensive. Most are 24V for vehicle use. It is much easier to charge them using a modern intelligent charger that can do all your batteries, such as the Turnigy Accucel-8 I use.
The PRC-350 uses a special and unique 15V battery. Most likely you will get a battery cassette, to take D cells. Invest in some NiMH cells for this, as using alkalines will cost a fortune. Likewise the PRC-349s use an odd 12V 600mAh pack, and if you did get one of these radios you'd most likely get a cassette with it. Incidentally ive got hundreds of these...
I'll talk about audio ancillaries in the next entry. This is quite a wide subject.
Over the past few days ive had my EKGSA antenna rigged on one of my 5.4m masts. This had to come down today, and did so shortly after the heavy showers. Luckily the showers held of for the duration of the Finningley clubs radio rally.
It was great wandering around in the sunshine deciding what junk I could get away with taking home! In the end though, I bought very little - a surface mount relay, and a Clansman Remote Handset.
You might notice that the handset has no cable... find out why in the next thrilling installment!
Thursday, 21 July 2016
Lazy radio day tomorrow?
With the nice weather, and some time off, I might decide to have a lazy day tomorrow, just sitting in the garden, reading and playing radio.
If I do, i'll put one of the 5.4m masts up with the EKGSA antenna for the PRC-352, probably also a dipole for the PRC-320.
Another thing I will do, is try pre-measuring the guy lines for the mast. It is possible to arrange the mast and guys in such a way, and with such pre-set lengths, that only a single person is needed to pull the mast upright and secure it. So long as the load on the mast head is not great, this could be done by a reasonably strong person.
If I do, i'll put one of the 5.4m masts up with the EKGSA antenna for the PRC-352, probably also a dipole for the PRC-320.
Another thing I will do, is try pre-measuring the guy lines for the mast. It is possible to arrange the mast and guys in such a way, and with such pre-set lengths, that only a single person is needed to pull the mast upright and secure it. So long as the load on the mast head is not great, this could be done by a reasonably strong person.
Good use for old dead batteries - Eliminators
ok, ok, yes I will get around to the next installment of the Clansman Manpacks for Amateur Radio article, maybe tomorrow i'll cover SURFs, Audio ancillaries and batteries. The final article will cover antennas and masts.
In the meantime, ive been working on sorting and testing the large number of 12V NiCd PRC-349 battery packs ive obtained.
Theres about a third of them in this photo. Those top left tested over 10V terminal voltage. Those top middle between 1 and 10V. The few at the right are a dry cell cassette, and a pair of good 15V Lithiums!
Inevitably, from how I came about these, there were going to be a large number that are dead. Most of these will end up going for recycling, after any good terminals have been salvaged. However, a very sensible thing to do with a couple of dead battery packs, especially for specialist devices, is to turn them into battery eliminators! I used to do this for the Kenwood radios I serviced when I worked for NTL, an eliminator allows you to power the radio from a mains PSU and makes alignment easier, as you dont have to ensure your using a good battery!
The first thing to do when making a battery eliminator is to find a dead battery that otherwise is sound, one with a duff cell but good case and contacts. The next step is probably the hardest part and the one that takes the most skill - opening the case. Here its good to have a few that you dont mind smashing while you work out the method! In the case of the 349 batteries, I found they are lightly glued around the top, which is recessed. A few gentle strikes around the seal with a sharp chisel and I was able to pry the top off.
Actually prying the top up was hard as the inside is packed with expanded polyurethane foam. Gently easing this foam out, expanding the gaps etc took a long time but eventually I was able to pull out the cells. Incidentally, the central tube should be possible to push out to give space to dislodge the cells. I'll try that trick on the next one I build. Remember to recycle the cells!
With all the old cells removed and the foam scraped out, I was left with the collection of parts shown below. This also shows the 4mm terminals and the fuse holder.
A bit of marking next and then drilling to create the three holes needed. Tightening the nuts for the sockets and fuse holder is a nightmare as there is simply no clearance inside the pack. Those for the sockets I managed to get tight, but the fuse holder is actually held in place by hot-melt glue!
Once all the innards are installed and wired up, a task that is best done by soldering the wires with the parts outside the case, and threading them through the holes, remembering also to thread the wires through the nuts, the wires were soldered to the terminals and the case closed. The tube was then pushed back in place. Both the tube and the top I secured with a little impact adhesive. Do remember to test the thing before gluing!
The final tasks were to push the securing bolt back into the tube, and fit a fuse. This should be a 1A fast blow type (20mm glass in my case), although its currently a 5A slow-blow in mine as thats all I had!
Another option is to install a grommet and trailing wires rather than sockets, i'll do the next one that way.
One of the 1Ahr NiCd packs for the PRC-320/-351 etc would convert into a very nice eliminator, but would require a 24V PSU. Another option there is to use a metal cased 4Ahr pack, and install a small 24v SMPSU and an IEC mains socket!
In the meantime, ive been working on sorting and testing the large number of 12V NiCd PRC-349 battery packs ive obtained.
Theres about a third of them in this photo. Those top left tested over 10V terminal voltage. Those top middle between 1 and 10V. The few at the right are a dry cell cassette, and a pair of good 15V Lithiums!
Inevitably, from how I came about these, there were going to be a large number that are dead. Most of these will end up going for recycling, after any good terminals have been salvaged. However, a very sensible thing to do with a couple of dead battery packs, especially for specialist devices, is to turn them into battery eliminators! I used to do this for the Kenwood radios I serviced when I worked for NTL, an eliminator allows you to power the radio from a mains PSU and makes alignment easier, as you dont have to ensure your using a good battery!
The first thing to do when making a battery eliminator is to find a dead battery that otherwise is sound, one with a duff cell but good case and contacts. The next step is probably the hardest part and the one that takes the most skill - opening the case. Here its good to have a few that you dont mind smashing while you work out the method! In the case of the 349 batteries, I found they are lightly glued around the top, which is recessed. A few gentle strikes around the seal with a sharp chisel and I was able to pry the top off.
Actually prying the top up was hard as the inside is packed with expanded polyurethane foam. Gently easing this foam out, expanding the gaps etc took a long time but eventually I was able to pull out the cells. Incidentally, the central tube should be possible to push out to give space to dislodge the cells. I'll try that trick on the next one I build. Remember to recycle the cells!
With all the old cells removed and the foam scraped out, I was left with the collection of parts shown below. This also shows the 4mm terminals and the fuse holder.
A bit of marking next and then drilling to create the three holes needed. Tightening the nuts for the sockets and fuse holder is a nightmare as there is simply no clearance inside the pack. Those for the sockets I managed to get tight, but the fuse holder is actually held in place by hot-melt glue!
Once all the innards are installed and wired up, a task that is best done by soldering the wires with the parts outside the case, and threading them through the holes, remembering also to thread the wires through the nuts, the wires were soldered to the terminals and the case closed. The tube was then pushed back in place. Both the tube and the top I secured with a little impact adhesive. Do remember to test the thing before gluing!
The final tasks were to push the securing bolt back into the tube, and fit a fuse. This should be a 1A fast blow type (20mm glass in my case), although its currently a 5A slow-blow in mine as thats all I had!
Another option is to install a grommet and trailing wires rather than sockets, i'll do the next one that way.
One of the 1Ahr NiCd packs for the PRC-320/-351 etc would convert into a very nice eliminator, but would require a 24V PSU. Another option there is to use a metal cased 4Ahr pack, and install a small 24v SMPSU and an IEC mains socket!
Saturday, 16 July 2016
Clansman Manpacks for Amateur Use - Part 2
In my previous post we discussed the unusable for amateur radio sets from the Clansman range, and the 'rare' but usable radios.
This time, we'll move on to the most suitable of the series, but starting with the 'least' suitable of them!
PRC-350
The PRC-350 is a 2W FM radio covering 36 to 57MHz in 25kHz steps. This means it covers the 6m band. Sadly, the current 6m bandplan uses 10kHz steps, which means only a few of the -350's channels coincide with a usable amateur frequency, and the FM calling channel is not one of them! It also uses a special 15v battery that is not compatible with any of the other radios. However, its does use the standard Clansman audio ancilliaries, and its antennas are the same as those of the more useful PRC-351. It does however have an internal 160Hz subtone generator which means it will work with non-clansman radios. As with the other radios we will talk about in this post, it also has dual audio connections. Originally, this was so that the operator could use the radio, usually with a headset, whilst a handset was available for the officer! There is also a mini-BNC antenna connector that allows this radio to be used with external antennas for increased range.
PRC-351
Of the VHF FM Clansman radios, the PRC-351 is understandably the most popular and most usable. Antenna compatible with the 350, battery and audio ancilliaries compatible with the PRC-320, it is a 4W FM set covering 30 to 77MHz in two seemless switching ranges at 25kHz channel steps. This means that although just like the 350 it is difficult to use on 6m, there are more channels usable on 4m, and this includes the calling channel on 70.450MHz. It is also possible, with a simple but tricky to carry out modification, capable of being made to cover a bit of the FM portion of the 10m band, by using a switch to 'fool' the synthesizer!
As with the 350, the 351 has an external antenna connection, in this case a proper BNC. This can be used with a number of Clansman antennas, which we will discuss later, or of course amateur antennas. But its main advantage is to connect it to a clip on 20W amplifier.
PRC-352 - The 351 plus 20W Amp
Adding on the 20W amplifier to the 351 redesignates it the PRC-352. At this point, the various whip antennas can no longer be used and an external antenna is required, but range is considerably increased. I myself have used my 352 and the Ground Spike Antenna to contact Bob M1BBV up on the summit of Ingleborough in the Yorkshire Dales, from Emley Moor, a distance of about 45 miles.
You may notice my PRC-352 above has another unit on top - a 4W SURF. We will mention these later. For amateur use, there is no advantage in having a SURF unit, if anything, they will actually reduce your signal!
PRC-320
The PRC-320 is the most popular of the Clansman manpack series, and with good reason. Build like the proverbial brick outhouse, the 320 is a 30W HF transceiver, capable of CW, AM and SSB opertion in 100Hz steps from 2MHz to 30MHz. Due to its rather agressive VOGAD mic amp, its 30W sounds more like 100W! Its built in manual ATU can match the radio to almost any antenna, although its best suited to capacitve (ie short) antennas. Only capable of USB 'as is', a relatively simple mod can add LSB capability. It does have a few curiosities in its operation, the chief of which is a 2kHz offset (the side-step) on SSB operation. Battery and audio ancilliaries compatible with the 351. However, unless you intend to use it only with resonant antennas, the 2.5m whip and the antenna gooseneck adapter are essential accessories. A tuning guide plate is attached to the radio body which shows what ATU settings are needed for various antennas, or what lengths of antenna wire for dipoles. A pair of clansman antenna wire spools, and a dipole center, are pretty much also essential accessories.
Prices for these vary considerably. A thick fin version is sometimes available, with reinforced protective fins over the controls, but commands a higher price. Budget radios can be had for less money, but expect some fins to be missing.
In the next post in this series, i'll talk about the antenna, battery and audio ancillaries suitable for use with the PRC-320, 351 and 352 radios.
This time, we'll move on to the most suitable of the series, but starting with the 'least' suitable of them!
PRC-350
The PRC-350 is a 2W FM radio covering 36 to 57MHz in 25kHz steps. This means it covers the 6m band. Sadly, the current 6m bandplan uses 10kHz steps, which means only a few of the -350's channels coincide with a usable amateur frequency, and the FM calling channel is not one of them! It also uses a special 15v battery that is not compatible with any of the other radios. However, its does use the standard Clansman audio ancilliaries, and its antennas are the same as those of the more useful PRC-351. It does however have an internal 160Hz subtone generator which means it will work with non-clansman radios. As with the other radios we will talk about in this post, it also has dual audio connections. Originally, this was so that the operator could use the radio, usually with a headset, whilst a handset was available for the officer! There is also a mini-BNC antenna connector that allows this radio to be used with external antennas for increased range.
PRC-351
Of the VHF FM Clansman radios, the PRC-351 is understandably the most popular and most usable. Antenna compatible with the 350, battery and audio ancilliaries compatible with the PRC-320, it is a 4W FM set covering 30 to 77MHz in two seemless switching ranges at 25kHz channel steps. This means that although just like the 350 it is difficult to use on 6m, there are more channels usable on 4m, and this includes the calling channel on 70.450MHz. It is also possible, with a simple but tricky to carry out modification, capable of being made to cover a bit of the FM portion of the 10m band, by using a switch to 'fool' the synthesizer!
As with the 350, the 351 has an external antenna connection, in this case a proper BNC. This can be used with a number of Clansman antennas, which we will discuss later, or of course amateur antennas. But its main advantage is to connect it to a clip on 20W amplifier.
PRC-352 - The 351 plus 20W Amp
Adding on the 20W amplifier to the 351 redesignates it the PRC-352. At this point, the various whip antennas can no longer be used and an external antenna is required, but range is considerably increased. I myself have used my 352 and the Ground Spike Antenna to contact Bob M1BBV up on the summit of Ingleborough in the Yorkshire Dales, from Emley Moor, a distance of about 45 miles.
You may notice my PRC-352 above has another unit on top - a 4W SURF. We will mention these later. For amateur use, there is no advantage in having a SURF unit, if anything, they will actually reduce your signal!
PRC-320
The PRC-320 is the most popular of the Clansman manpack series, and with good reason. Build like the proverbial brick outhouse, the 320 is a 30W HF transceiver, capable of CW, AM and SSB opertion in 100Hz steps from 2MHz to 30MHz. Due to its rather agressive VOGAD mic amp, its 30W sounds more like 100W! Its built in manual ATU can match the radio to almost any antenna, although its best suited to capacitve (ie short) antennas. Only capable of USB 'as is', a relatively simple mod can add LSB capability. It does have a few curiosities in its operation, the chief of which is a 2kHz offset (the side-step) on SSB operation. Battery and audio ancilliaries compatible with the 351. However, unless you intend to use it only with resonant antennas, the 2.5m whip and the antenna gooseneck adapter are essential accessories. A tuning guide plate is attached to the radio body which shows what ATU settings are needed for various antennas, or what lengths of antenna wire for dipoles. A pair of clansman antenna wire spools, and a dipole center, are pretty much also essential accessories.
Prices for these vary considerably. A thick fin version is sometimes available, with reinforced protective fins over the controls, but commands a higher price. Budget radios can be had for less money, but expect some fins to be missing.
In the next post in this series, i'll talk about the antenna, battery and audio ancillaries suitable for use with the PRC-320, 351 and 352 radios.
Subscribe to:
Posts (Atom)