Wednesday, April 07, 2010

Broken duck

I went for another stroll up Tallentire Hill this afternoon with the TH-F7E. The FT-817 is tied up running my EchoLink hotspot until I can find something cheap I can dedicate to the task - I have my eye on a pair of PMR446 radios that are modifiable to 70cm.

I took along my DIY 2m rubber duck antenna and a "Black Rod" 2m 5/8 telescopic whip that I recently bought on eBay. In case you are wondering, I use an "HT Saver" SMA to BNC adapter to take the strain of the longer whip. But I am seriously considering using the TH-205E for such outings in future, if I can sort out a battery pack for it, because it has a proper BNC antenna socket and is much better suited to use with a large telescopic whip.

The 2m FM channels were not exactly buzzing with activity but I heard the GB3CS repeater 100 miles away and a GW station (Wales) in QSO. I tried swapping the two antennas for a comparison, but could hear nothing on the rubber duck at all. This surprised me, as the last time I did a comparison there was hardly any difference between it and a quarter wave telescopic, and I didn't expect the 5/8 to make such a huge difference.

The TH-F7E is multimode on receive, so I took a listen on 2m SSB as well. I heard the GB3NGI Northern Ireland beacon much stronger than I can receive it from here. But I couldn't hear GB3VHF from South East England at all. I haven't heard it from home at all recently either, although it is supposed to be back on the air after a move to a new location. I guess the new location isn't as favourable as the one it has operated from for longer than I have held a ham radio license. GB3VHF was the first amateur 2m signal I ever heard, after building my first 2m receiver, so hearing its call in Morse always causes some nostalgia.

I put out several CQ calls on 145.500 and was eventually called by Bill G3WJH in Seaton, only a few miles away by line of sight. I swapped the antennas again, and he couldn't hear me at all on the duck. Colin, 2E0XSD then joined us, and then we were called by Richard G0IBE/P on Lord's Seat (a SOTA and WOTA summit) so we all exchanged reports with him for chaser points. Jim G3ZPD from just south of Cockermouth then called in and worked Richard as well. By that time I was getting a bit chilly as it was a lot colder up there than it was at home, so I came back.

On my return I checked the DIY Duck on my antenna analyzer and found an infinite SWR. I pulled off the whip and the copper wire had fractured just about level with the top of the BNC adapter, which is probably the point that experiences the most bending. I guess 22SWG enamelled copper wire isn't flexible enough to use for a helical antenna. Back to the drawing board.

1 comment:

Tim_Hague said...

GB3VHF is not on the air as yet, but it is hoped that switch on will ne next week. If you would like to donate to the running costs of this wholly donation supported internationally known beacon please see