Un-tuner

Once again ive had the lid of the ATU. I did so a couple of days ago when my curiosity got the better of me and i decided to take a look inside, and im glad i did. The connection from the capacitors to the inductor was dry joint and loose, and the inductor itself was slightly deformed. I resoldered the joint and repositioned and straightened the inductor.

Today, whilst messing trying to calibrate the antenna, i decided to switch to the dummy load and check the rig in straight through 50 ohm unbalanced load. Hmmm, SWR 1.1:1? should be perfect? wait a minute! 30W? im running 10W?!

so, out came the bird meter and the 25W load. Ive only got a 25-1000MHz element for the bird, so set the alinco on 24.990 and low power - perfect 10W, so, the old MFJ is out of cal.

Ive now calibrated the low power (30W range) of the ATU both forward and reversed in bypass mode to the dummy load at 10W. Ive also calibrated the high power (300W) forward reading, this being done on 3.8MHz at 100W to aerial, as ive no suitable load for this power, and the antenna can tune a 1:1 SWR on 80m.

It just shows, its worth taking the time to check 2nd hand gear carefully! The antenna is still no better, but at least any readings i take from the MFJs SWR bridge are meaningfull now.

Antenna Work

The coax originally connecting the antenna (in its G5RV form) was removed long ago in favour of all balanced line. But, this unfortunatly puts the feeder/element combined lengths at a rather unfortunate multiple of 1/4wavelengths for my main bands, and so getting the thing to tune up well isnt easy, and on 40m the low SWR point is very sharp. Im going to add another 13ft of feed to hopefully bring the length away from the current wavelenth multiples that are creating the high impedance problems. The new feedline arrived today, and so hopefully i can get it patched in soon. Ive also constructed a coaxial balun that i will try in place of the ATUs internal toroid, which i dont have great faith in.

Shack-a-rama

ok, so the shack in the bedroom was to be moved, as can be seen it was pretty cramped
so the sunroom cupboards came out, and it moved in there, after re-using as much material as i could, the result is a custom shack, neatly built in one corner.
top shelf - RX-2cc weather satellite APT receiver; MVT-7100 scanner; 2m 30W linear; Ft-290mk1; vase of artificial flowers.

main shelf/desk - FRG-100; DX-70TH; ATU; phone. Logbook and a pair of coasters. Underneath - dustbin; boxfile of manuals; cables etc; 30A PSU (not visible cos on floor)

QRV HF

ok, were in business!

after a couple of hours of sheer terror up Micks rickety ladders, and 20mins or so explaining to my little boy what i was doing whilst wedged in a tree, the G5RV is up. Ive had to use the coax that was feeding 2m, so im now QRT on 2. But the MFJ tuner and the Alinco DX-70TH, G5RV combo is working fine, already getting me several special events and IOTAs in the log. Im still calibrating the G5RVs tuner settings, and this ive only completed on 80m, 40m and 20m, so these are the bands im active on. Conditions on 80m are abysmal, the QRN is very strong, so 20m is prefered.

It doesnt help, whilst trying to work a special call (in this case GB100TT) to have more than the usual number of lids who insist on tuning up on the frequency (like a 3kHz QSY is really going to affect the SWR!) or those who insist on calling the station even though they are already in QSO. Its not difficult to tell when a station is in QSO or when ready for a call, if the last thing from them wasnt QRZ or CQ, then DONT call!!! Its just pure ignorance, and spoils it for those without 3el triband beams on 100ft towers and who cant run a 1kW amp. I at least can command 100W, but i do feel sorry for QRPers trying to work against such ungentlemanly conduct.

Wood, Sweat & Tears

The shack move is coming along nicely. This is how it looked in the spare bedroom


quite a shambles as you can see. Being that close to the computer wasnt good for my signal to noise ratio, and even a mild 10W on HF would knock the ADSL modem off-line.
And this is where im moving to -


There was a tall narrow cupboard in the corner, but thats now providing material for me to build a custom desk with

the main desktop is 24" deep, enough for equipment and writing space, so long as theres nothing jutting out the back. To accomodate wiring etc, the desk is mounted forward from the wall with a 2" gap. The same gap is to be maintained for the shelf above the desk (the VHF/UHF shelf). Eventually, the whole of the under side will be shelved (again with a cable gap), and a cupboard door fitted, apart from a 9" space next to the wall. This will be open and will house the high current PSU and battery chargers.

For now the shack is temporarily squashed up even more-

My new logbook, and the G5RV have arrived. Im now working on getting hold of a couple of scaffold poles for use as masts for the yagis for 6m and 2m.

Shack Movin'

At present, the shack is one half of the spare bedroom. It is also a computer room, and an office. This is not ideal, and if we decide to have another child, then it will become a nursury, and i would be forced to vacate.

So, thinking ahead, ive decided to relocate the shack to the downstairs backroom. When i think about it, this makes perfect sense -

It shortens all the feeder runs considerably (except for the cable to the WX sat crossed dipoles);
It drastically shortens the ground connection;
It puts me, when operating at night, diametrically as far from the missus as possible, so i wont disturb her sleep;
It means that i can use the radios and still be near my family in the front room;
It also means i can customise the shack furniture

It involves some quite serious woodwork, and rearranging the room, but i can make it neat and tidy.


On more directly radio related notes, Ive got a G5RV on order, which should be more effective than the random wire, and a logbook is on its way. Ive also secured an exchange of FT-290s, giving me a unit with a MuTek front end (and working backlight!). This and the 30W linear are going to be mounted on a wooden carrier, so i can rapidly move them for mobile or portable use, as well as base. Im also in the process of ordering the aluminium stock to build a 3 elelment 50MHz yagi.

coming up

ok then, since the first post on here, some wheeling and dealing have aquired me -

25A variable PSU (to run everything)
MFJ -948 Antenna Matching Unit
Alinco DX-70TH HF + 50MHz transceiver

the first thing done to the alinco was to lock out the Tx! this is a safety measure until i have got the antenna working properly, and to stop my lad from keying it up.

A new RF ground gets installed tomorrow, hopefully then the wire antenna will load up satifactorily.

So far the DX-70 seems just as sensitive on Rx as my FRG-100. The only gripes are - A, there is no REC output, so in order to feed audio to the PC i have to lose the speaker output. B, the filters are not as sharp. But these are minor compared with the generally increased capabilities, not to mention the reduction in size.

Hullo!

I'm Martin G7MRV, this blog is more a sort of diary for me really, just an occasional ramble about what im up to radiowise,

anyway, a bit of background is in order to start with - aged 31, interested in radio since age 13, licensed radio ham since age 15. Recently reactivated my callsign after a few years break. Slowly getting back into it all.

Equipment - Yaesu FT-290Rmk1 2m multimode; Microwave Modules 144/30-LS linear amplifier; Yaesu FRG-100 HF comms receiver; RX-2cc weather satellite receiver; various homebrew/commercial items (handhelds/ testgear etc)

ok, the story so far...

Not got around to much operating on 2m yet despite having had the 290 for some weeks. I have yet to install the muTek front end board, as i cant seem to get any installation details. The linears preamp seems to be working, at least the noise gets louder! cant really run it at full whack yet as its only on the 12v 7Ahr solar power system intended for the weather sat and the meteorological instruments. Hopefully will get the mutek in soon, and a high current PSU that will run the linear and whatever HF rig i end up with. I would prefer a solar/wind solution to the high current requirements, but im not sure i can afford it.

Im watching out for a HF + 6m rig, probably an Alinco DX-70TH if i can, as i think they receive better on low bands than the other rigs on the market.

Heres the general wish list to get my station back up and fully operational =

2m Multimode - got, FT-290Rmk1
2m Linear Amp - got, MML 144/30-LS
general rx/airband - got, MVT-7100
Primary HF receiver - got, FRG-100
Secondary HF receiver Target HF-3/4 or DX-394 maybe
HF + 6m Transceiver DX-70TH or IC-706mkIIG
25-30A 12v supply
Auto ATU
2m Beam
6m Beam
rotator
small 2m FM mobile Icom IC-229 prefered