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[Amps] electronic switching

To: <amps@contesting.com>
Subject: [Amps] electronic switching
From: G3SEK at ifwtech.co.uk (Ian White, G3SEK)
Date: Tue Jun 24 08:56:17 2003
G3RZP wrote:
>
>Vic said:
>
>>If you have a rig with decent QSK it can be great
>
>I took a dislike to QSK back in the days of separates and real radios that
>glow! Tried and didn't like it - OK with big strong signals and not too
>much noise. I expect it was fine for maritime stuff on the 500kHz band when
>passing traffic to coast stations who had good signals.
>
When thinking about new features for the next-generation Triode Board, I 
surveyed a number of CW users about QSK (ie the full listen-between-the 
dots facility).

The overall conclusion wasn't too surprising - some users swear by it; 
others swear at it!

Obviously QSK is valuable when passing large blocks of solid traffic, 
where the receiving station can break in immediately when a repeat is 
needed. But that isn't amateur radio (at least, not in most of the 
world).

The same applies when ragchewing... but only up to a point: in a normal 
conversation you let someone at least finish a thought before 
interrupting, and semi-BKIN with a short hang time and pauses between 
sentences will do fine for that. You don't need full between-the-dots 
QSK to interrupt someone in mid-word.

Many people seem to use QSK in a few specific situations only, for 
example so they'll know when to stop calling in a pileup. The sooner you 
know that the DX has gone back to someone else, the better your chances 
of tuning to find where he's listening. That does seem to be a real 
advantage for QSK; at least, I've found it so.

QSK is much less useful when you're the one calling CQ, or when you're 
'running' in contests. In this kind of operation, the exchanges are so 
short that there's no point in trying to break in part-way. Anyhow, the 
routine parts of DX/contest exchanges are often computer-generated these 
days, and even if the operator can listen through, the computer won't 
stop sending until it's finished.

Many SO2R contesters not only don't use QSK, they don't even use 
sidetone while sending automated CQs and exchanges. They grab those few 
seconds to listen on the second radio, usually on a completely different 
band, so they definitely don't want anyone breaking in.

All of this seems to add up to a very limited role for full QSK in 
modern-day amateur radio.

However, since a significant minority of CW ops use QSK at least some of 
the time, and the amp always needs to switch very quickly at the start 
of a transmission (see below), the next generation of the Triode Board 
will support it.

>But as Vic says, most modern rigs are pretty poor.

And so are many mid-range modern amps. For most amp owners, the 
important thing is not full QSK capability, but simply the ability to 
switch safely and reliably before the RF arrives from the transceiver at 
the start of a transmission... and many amps don't even have that.


>Interestingly enough, it
>seems that many of them just aren't that good on overall CW performance,
>such as clicks.

Any FT-1000 owner who hasn't done the W8JI or Inrad keyclick mods is a 
public nuisance! See www.w8ji.com and/or www.qth.com/inrad

Combine poor transceiver keying with amps that are hot-switching due to 
slow relays, and you really have trouble!


-- 
73 from Ian G3SEK         'In Practice' columnist for RadCom (RSGB)
                            Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek
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