[Amps] Ten-Tec Centurion
R.Measures
r at somis.org
Thu Nov 11 09:42:51 EST 2004
On Nov 11, 2004, at 4:53 AM, Ian White, G3SEK wrote:
> R. Measures wrote:
>>> Assuming the spike is at the leading edge of the transmitted signal,
>>> then an
>>> rf sensing circuit could delay the turn on of the rf amplifier until
>>> after
>>> the passing of the spike.
>>
>> Colin -- The problem is that incoming RF does not go on a
>> mini-vacation immediately after the spike, it merely backs down to
>> the ALC level that is set. Thus, there is RF on the closing NO
>> contacts while they are bouncing. This results in hot-switching and
>> current-transients.
>>
>
> Also there are two sets of relay contacts, at input and output. These
> contacts will bounce, and even if they are on the same DPCO relay,
> they will not bounce exactly together. This means the PA can have some
> exciting moments
Englanders, the masters of understatement.
> when the input relay is closed but the output contacts are not. The PA
> then has full drive but no load, which could lead to very high
> voltages across the tank components.
Ian -- Would not the Load-C be likely to arc with no load?
>
> All of that can happen without any kind of oscillation, either at the
> signal frequency or parasitically at VHF.
Agreed.
>
Richard L. Measures, AG6K, 805.386.3734. www.somis.org
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