[UK-CONTEST] CQ WW SSB 2007 - GM0F (long)
G3SJJ
g3sjj at btinternet.com
Wed Oct 31 04:50:11 EST 2007
OK, looks like the antenna then.
I removed all the audio leads, DX Doubler and mHam Keyer out of circuit,
then used the second coax run directly to the 40m phased array as well
as dissing all the 24v relay connections to the phasing relay box. At
that stage there was no feedback. I re-connected all antennas and DC
lines and everything was still clear. I re-connected the audio cables,
but not including the DX Doubler, and the RF feedback was back again. I
then wound 2 turns round a clip-on ferrite on the lshort extension lead
that goes from the Heil mic mini-jack plug into the mHam Keyer and the
feedback was slightly reduced. Winding about 5 turns round a 40mm OD
toroid effected a complete cure.
What is puzzling is that the 40m array is about 130m from the shack yet
the problem is only on 40m, so I am still convinced there is RF on the
various cabling back to the shack, ie 2 coax runs, 2 x 7 core from
Sixpak, 7 core rotator (6 core plus 7th core for 24v phasing relay
switching.)
Al G0XBV suggests it could be the MP mic socket which isn't grounded and
G4IIY suggests it is the Heil headsets picking up RF. Again I can see
these could be contributors but why only on one band?
Whadaya mean, SJJ on SSB? If I can decode a mode with my own brain then
I am happy to use that mode! CW is best though!!
73 Chris G3SJJ
Cooper, Stewart wrote:
> Hi Chris,
> I actually removed the entire audio circuitry (DX Doubler, Headset,
> voice keyer, etc), and tested with the original Yaesu fist mic and I
> STILL had RF feedback! I even had some whickers with the amp out of
> circuit!! I do have all the parts of my audio screened and bonded
> together, and have ferrites on every in and out of each box. In fact it
> looks a mess. And yet only on one band - 15m. I had no indication of the
> bad transmit quality by using the monitor facility - this sounded fine
> at all times. I think the coax screen has become disconnected at the
> antenna/balun end or something - I can't see. The feeder is old too. I
> couldn't face lowering the whole lot (I also have 2m and 70cm on that
> tower) during the contest. The match went to 3:1 a few weeks ago, and I
> replaced an in-line connector and all was (apparently) better. I need to
> get some hard-line up that tower anyway, so now is the time.
> G3SJJ in an SSB contest! Well I never...
> 73
> Stewart
>
> -----Original Message-----
> From: uk-contest-bounces at contesting.com
> [mailto:uk-contest-bounces at contesting.com] On Behalf Of G3SJJ
> Sent: 30 October 2007 17:48
> Cc: UK Contest Reflector
> Subject: Re: [UK-CONTEST] CQ WW SSB 2007 - GM0F (long)
>
> I fully empathise Stewart, which why I have opted for doing multi-op
> entries in 48 hour contests!
>
> I also had RF feedback problems, just on 40m, and came to the conclusion
> like you that it was the antenna. Well, how wrong can you be? Ian G4IIY
> confirmed that he also had experienced RF FB. It was only AFTER the
> contest that I tried ferrites on the Heil headset lead and achieved 100%
> reduction. Worth a try!
>
> Chris G3SJJ
>
>
>
> Cooper, Stewart wrote:
>
>> Sadly, this year's CQ WW SSB was a complete non-event, but as Dave
>> prompted for some stories here's mine. I had a few issues which really
>>
>
>
>> put a damper on my enthusiasm (which doesn't take much to dampen these
>> days) and my score.
>>
>> I entered the Assisted section. I don't know why, when you're given
>> your mults on a plate, the rate just falls through the floor. I think
>> it's essential to ignore the cluster until at least midnight on
>> Saturday night! Strangely, as others have said, it's not Single Op
>> Assisted, it's Single Op Distracted. This was borne out by my rapidly
>> failing score on Saturday morning. Using the wonderful WinTest
>> objective facility I could see that I was falling behind after 0400
>> without any let-up on my enthusiasm up till then (compared to 2005).
>>
>> My 15m signal was awful. I was given a couple of 'bad audio' reports
>> when I started running on 15m, although I was unaware of the cause. I
>> listened on my second radio, and sure enough, it was awful. I
>> disconnected everything that might have allowed RF in, but to no
>>
> avail.
>
>> I tried running using the second radio (FT1000MP + Collins 30S1) and
>> it was as bad. Very strange when you get RF feedback in the same
>> manner on two separate radios! It looks like it's the antenna. I had
>> to repair the feeder last week, so perhaps there's more to the problem
>>
>
>
>> than meets the eye. So 15m was out of the frame.
>>
>> I couldn't copy stuff on 20m. This was a real pain. Conditions were
>> good and the band was busy. I now realise that I am not better than
>> the radio. I've always refused to buy additional SSB filters for my
>>
> radios.
>
>> I now realise that I'm not better than the radio, and that filters are
>>
>
>
>> an essential part of a decent transceiver. I nearly bought two new
>> ones last night!
>>
>> 160m set the phone off. Every time I transmitted on 160m I set the
>> house telephone off. It's done this in the recent past but I never
>> really dwelt on it. This was serious and I couldn't go on. As to why,
>> I have no idea. Was it doing it to the next door neighbour's phone
>> too? Up until July this year it was not a problem, and nothing on 160m
>>
>
>
>> (or the phone
>> system) has changed. In fact I actually removed the phone line from
>> the shack earlier this year. It must be RF getting in to the actual
>> phone line, which passes by the antenna field at about 20 feet high.
>> Very simply, it must be over-powering the phone. So, no 160m either.
>> 10m was open and was jumping, but for me, only with lots of Europeans.
>>
>
>
>> I called CQ and worked strings of DL's and OE's. I felt this wasn't as
>>
>
>
>> productive as it might have appeared at first.
>>
>> I have some horrible bug which I caught in Ghana a few weeks ago which
>>
>
>
>> I can't shake off. Have now been put on a course of some extremely
>> potent anti-biotic. I'm run down. (Just adding this to the list of
>> excuses!)
>>
>> But it was the 20m and filtering problem which finally did it for me.
>> I find it incredibly difficult to walk away from a contest. It takes
>> me to a place I don't want to go (mentally). I am tired for a start,
>> which I am not good at handling these days, as mild paranoia seems to
>> creep in (I think - I'm not an expert). Then I just get so depressed
>> once I have had a sleep because I feel that I could rescue the
>> situation, but then another side says - no way, you're .5 mil points
>>
> behind already.
>
>> So, last night I booked my flight to operate at CT9L in November!
>>
>> Operating time : 14h50
>>
>> BAND QSO CQ DXC DUP POINTS AVG
>> --------------------------------------
>> 160 0 0 0 0 0 0.00
>> 80 223 13 69 2 292 1.31
>> 40 148 15 71 0 242 1.64
>> 20 364 20 78 1 622 1.71
>> 15 44 11 33 0 81 1.84
>> 10 139 9 41 1 180 1.29
>> --------------------------------------
>> TOTAL 918 68 292 4 1417 1.54
>> ======================================
>> TOTAL SCORE : 510 120
>>
>>
>> Stewart Cooper
>> Maintenance Systems Engineer
>>
>> ODL
>> Buchanan House Summer Street Aberdeen UK AB10 1SJ
>>
>> Tel (Direct) +44 (0)1224 628039
>> Tel (S'board) +44 (0)1224 628000
>> Fax +44 (0)1224 643325
>>
>>
>> ----------------------------------------------------------------------
>> --
>>
>> _______________________________________________
>> UK-Contest mailing list
>> UK-Contest at contesting.com
>> http://lists.contesting.com/mailman/listinfo/uk-contest
>>
> _______________________________________________
> UK-Contest mailing list
> UK-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/uk-contest
>
> Scanned by IFB SafeMail http://www.ifb.net for virus content.
> IFB Spam-Score:whitelisted
> ------------------------------------------------------------------------
>
> _______________________________________________
> UK-Contest mailing list
> UK-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/uk-contest
More information about the UK-Contest
mailing list