----- Original Message -----
From: <gary@7-media.net>
To: "K1TTT" <K1TTT@ARRL.NET>
Sent: Sunday, December 07, 2008 3:04 PM
Subject: Re: [Amps] rx noise?
> Hi
> '
> Check your parasitic suppressor in the plate circuit. The symptoms you
> describe point to the amp taking off.
>
> The fact the plate voltage was down a little suggests it is operating
> whilst on receive.
>
> You may also have a bias relay contact problem. Often amps have a relay
> contact that allows the bias to increase on receive and thereby turns the
> tube off
>
> during receive and that may be a dirty relay contact etc.
>
> Cheers and good luck
>
> Gary ZL3SV
>
>
>
>
>
> ----- Original Message -----
> From: "K1TTT" <K1TTT@ARRL.NET>
> To: "Amps" <amps@contesting.com>
> Sent: Sunday, December 07, 2008 4:11 AM
> Subject: [Amps] rx noise?
>
>
>>I have a commander hf-2500 (pair of 3cx800a7's, no qsk) that seems to be
>> working fine. However, during cqww cw last week I had to pull it off the
>> 20m station because it was making a broadband noise while on receive. I
>> put
>> it back on the station today and it isn't doing it now. I tried warming
>> it
>> up a bit and it still didn't do it....though its obviously not as warmed
>> through as after 40 or so hours of cqww. The only other thing I noticed
>> is
>> when it was doing it the plate voltage dropped a bit, maybe 50-100v, but
>> I'm
>> not sure if that was a cause or effect since the line voltage sag from
>> the
>> other stations can make the hv sag a bit here. Any ideas where to start
>> looking??
>>
>>
>> David Robbins K1TTT
>> e-mail: mailto:k1ttt@arrl.net
>> web: http://www.k1ttt.net
>> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>>
>>
>>
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>
>
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