Wednesday, 21 October 2015

Ex-PMR antennas on ham bands

Many years ago, when I was first starting out in amateur radio, at our local club (Mexborough ARS) there was much fuss over a supply of ex-PMR VHF collinears, known as 'Sam's Specials' as a result of the supplier! Quite a few of us around the South Yorkshire region had these for 2m, I think he charged £15 for them. I dont know what band they were cut for, but one of the standard 'Pye' bands covered 2m.

Ive now acquired a pair of ex-PMR UHF collinears. These are marked as being 440-470MHz. Just how well they will work on 70cm I will need to find out by testing. Sadly, the antenna guys decided it was too much effort to remove the weatherproofing and disconnect the coax, so they have just been cut off above the connectors.

The weather has attacked the end of the coax, but luckily, its not spread more than a few mm into the cable. Theres just about enough cable to put a connector onto, so long as I get it right first time! I decided to use this one as the test antenna, despite the fact that the other one has much more cable to work with (about six inches!) and this one is the hardest to work with, since I wanted to see just how bad the corrosion had got. I know that, if the antenna proves useless on 70cm, ive wasted the effort.

If they are no use as is on 70cm, then they will be opened up and either modified, if thats possible, or a different antenna built inside them.

Ive also today, taken the plunge and ordered a channel crystal pair for the Pye PF8. Ive opted for the 70cm calling frequency 433.500MHz. I wont be able to ragchew on it, but decided for general rally use etc the calling channel was probably the sensible option.

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