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[Amps] re: EBS at soft or quiet moments

To: <amps@contesting.com>
Subject: [Amps] re: EBS at soft or quiet moments
From: G3SEK at ifwtech.co.uk (Ian White, G3SEK)
Date: Mon Aug 4 08:39:30 2003
> In the 2 meter amplifier after a 3 minute CW transmission at about 20
>wpm
>into a dummy load, the average anode exhaust temperature went from 205
>degrees F
>to just under 100 degrees F when using the EBS.

This is the aim.

EBS seems to have a poor reputation because of either:

1. Being the only means of keying the amplifier, which is guaranteed to 
cause hot-switching. Competent EBS works along with the hard-wired PTT 
line - it cannot replace it.

2. Being RF-actuated at too high a level (ON4UN suggests around 0.5W in 
a kW amplifier, related to the dynamic range of he speech processing for 
SSB).

3. Being too slow to turn on.

Any or all of the above can cause a poor signal, and then of course 
there's:

4. Being unreliable and easily damaged.

... but it doesn't have to be that way.

Like many other features in amplifiers, EBS can be very useful if it's 
competently done - or a disaster if not.



-- 
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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