>
>Hi Chris,
>
>> Hello all
>>
>> I've looked through the archives and can't see much about the AL-80.
>> I've just purchased an early model AL-80 and would like to modify
>> it/upgrade it before using it.
>>
>> I know that there were some parasitic oscillation problems with these
>> early models - can anyone tell me how the AL-80A and AL-80B have been
>> improved ?
>
>I never heard that rumor about early AL-80's, except from Rich
>Measures. He attributes any failure, no matter what the actual
>cause, to parasitics.
? Only when there is collateral evidence. The good news is that what
appears to be parasite damage in single 3-500Z amplifiers (such as the
AL-80 .series and SB-1000) is less common than it is 2, 3-500Z amplifiers
-- probably because there is twice as much anode/cathode feedback-C in a
"2-holer". .
>
>If you feel more comfortable, make mods...but they won't cure
>problems that aren't there.
>
? good point. To find out if your AL-80 hotswitches, observe the swr
meter on your transceiver during PTT operation. If the swr indication
spikes as the button is pushed, hotswitching is indicated. // In my
opinion, hotswitching can cause problems.
>The bulk of failures in early AL-80's (made by Amp Supply prior to
>Prime Instruments recalling the line do to a bad debt)
? whose bad debt, Tom?
>...........
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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