[UK-CONTEST] CC April CW TX Bandwidth

[Andy Cook, G4PIQ]

Sorry to come late to this discussion - was tied up over the weekend. I
think the other reason that Clive might well have got away without a key
click mod in the circumstances of operating +/- 10 kHz is that key clicks
are probably not the dominant problem here - phase noise, broadband Tx noise
and blocking dynamic range, are and the MP is pretty good in those respects.


Key clicks become a real problem at much closer spacings like 500 Hz or 1
kHz spacing but from moderate signals rather than just really huge ones. In
theory in CW you can make decent use of really narrow filters and this
should make CW contesting much less congested and more pleasant than SSB
contesting. Well - that's only half true right now. Some signals are very
clean and you can operate say 300 Hz away from them with no issues, but
that's not the case if the other operator is using an un-modified FT1000MP.
The clicks from these stations in CW contests cause just as much frustration
as QRM from adjacent SSB QSOs in SSB contests. 

I've only modified the MPs I use in contests in the last 3 years or so. It
took me getting really irritated at the number of QSOs that other people's
clicks were busting for me to realise that anyone operating CW with an MP
and a moderate station really must do the mods. They are simple to do and
make a huge difference.

There are those folks who say - I don't want to do that because it means
that others can operate much closer to me. I don't buy that as an acceptable
answer - it's like the use of 6 kHz filters on SSB transmit, or
intentionally over-driving your amplifier or pushing it out of class AB,
using the grid current warning LED in a grid drive tetrode amp as the the
'on' light.... The more people that we can persuade to fix the problem by
peer pressure the less trouble we all will have

73,

Andy, G4PIQ

-----Original Message-----
From: uk-contest-bounces at contesting.com
[mailto:uk-contest-bounces at contesting.com] On Behalf Of Ian White GM3SEK
Sent: 11 April 2009 19:42
To: uk-contest at contesting.com
Subject: Re: [UK-CONTEST] CC April CW TX Bandwidth


Clive Whelan wrote:

>> There does seem to be some variability between individual rigs, but 
>> even the best of them are clicky and the worst are downright 
>> horrible.
>
>Well myself and GW3RIH must have been very lucky in getting a couple of
>good 1000MPs then, because we lived 500 yards apart and both ran 400w, 
>me using an Alpha 78 and Wes using a TL922, and we could operate within 
>10kHz of each other on 14Mhz , without insurmountable problems 
>problems. You don't suppose that could have been because we didn't 
>overdrive the amplifiers do you? ;-)
>

No, the problem is definitely with the transceivers themselves.

However, if you were using your amplifiers at the 400W level, the 
transceiver output power would have been only about 20-25W. That might 
have helped to reduce the levels of key clicks, though it wouldn't have 
been directly due to the reduction in power - more likely the effect it 
might have had on the ALC dynamics.

Nobody has really got to the bottom of why it happens... least of all 
Yaesu.


-- 

73 from Ian GM3SEK
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