The 4 m Forum

PA5DD · Posted: Mon 14 Apr 2008, 09:46 Post subject: What is the matter with GB3BAA/b ?

Does anyone know, what has happened to GB3BAA. I can still hear it, but it is way down (in the order of 6dB) on what it was in the past, such as last year around this time.

I sort of miss it, as it was the only beacon that I hear constantly on Tropo.

This weekend it went so far, that I installed my 7ele monster on the roof, just to hear the beacon again:

http://home.hccnet.nl/uffe.noucha/log/7ele_roof.jpg

73 Uffe PA5DD

G4MDC · Guest

Thanks for the report Uffe. I wasn't aware of anything the matter but I have listened here at about 35km away on my TS700 (converted) and with Halo and GP antennas (Scientific measurement methods) and I can understand what you say. About S3 in place of S9 here.

I will try to look at it when the opportunity arises. It maybe that the cavities are off tune. They allow co-site working of MB7FM on 70.4375. I was thinking the parrot RX was down too lately so maybe cavity retune time is coming? Days get longer and WX gets better...fortunately HI

PA5DD · Posted: Tue 15 Apr 2008, 07:05 Post subject:

Thanks a lot, Jon.

It is a very useful beacon, and I was quite surprised to hear it constantly, when I got on the band in 2005. After all it is at a distance of 374km and my antenna is only clearing the roof top (7m AGL = 5m ASL).

I have an idea that the deterioration started, when the parot was off air for a short time last year - but now I'm just guessing.

73 Uffe PA5DD JO22IC

G3PTU · Joined: 25 Jan 2006 Posts: 287 Location and locator*: IO93

I also confirm the beacon is very low level both in Yorkshire and where I am now at the moment in Rennes Britanny.
I fact its gratifying to read that others find it so because I thought there was some wrong with the rx / ant here.
The 10m beam had suffered in the violent wind they had last month, all the vital bolts where loose / had fallen out.
David F/g3PTU

G4MDC · Guest

A month to the day (ashamed) I can report only 3W out.
QRT for investigation...back soon hopefully depending on the stock levels of any bits required!

PA5DD · Posted: Wed 14 May 2008, 18:27 Post subject:

Nothing to be ashamed of, you are running a fine beacon. The 3W normally visible in FFT program Spectran here. Yesterday evening, there was a lift and I even copied GB3BAA/b with 549.

Wishing a speedy recovery of the output.

73 Uffe PA5DD

G4MDC · Guest

Yes Uffe - my spies tell me about your spot yesterday...
Herewith the pronouncement...

I hate PL259s!!!

The output socket is one of these (because it is a PMR transmitter of some age). I would change it but it would need a CNC workshop and more patience than I have. So it has an adaptor cable to N type.

The adaptor cable had gone intermittent 2W was 3W or 2W again as you wiggle it.. Remade PL259 connector - not intermittent any more but still only 3W. Tuning i can get 10W max (not good)

The output matching shows some heating has happened. Since retuning was no good it now has a new SD1015-5 PA transistor (not many of these left in the box) and so it does about 30W at max and is soaking happily at the usual 15-16W. Maybe it will go back tomorrow if it is well behaved.

And I still hate PL259s!

PA5DD · Posted: Fri 16 May 2008, 06:43 Post subject:

Not too strong today because of the conditions, but continous speaker copy none the less. A very welcome signal is back !

Thanks for the effort,

73 Uffe PA5DD

G4MDC · Guest

Good Uffe and Tnx report. I am going to check it again today if I can find time to visit. Just to make sure after 24hrs all is still OK.

G4MDC · Guest

All OK Pleased to say.