[Amps] Alpha 87a Low receive

['DGB']

I solved my problem by not using the PAPTT from the microham MKII. Don't 
know why but plugging it into the K3 directly took care of the 
low-receive problem.

thanks for all the info.

73 Dwight NS9I


On 6/13/2016 5:03 PM, Jerry wrote:
> The TX and RX pin diodes have been remarkably reliable with infrequent
> failure.  The best explanation for pin diode failure is the system setup -
> see the following link several years ago by John, W0UN which still holds
> true today.  Read the final paragraph which I can confirm personally as
> well.  Also, Verical (Arrow) is selling the TX pin diodes for only $45 and
> still had hundreds in stock.
>
> http://lists.contesting.com/_amps/2003-01/msg00004.html\
>
> 73  Jerry NY2KW
>
> -----Original Message-----
> From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Robert Arenella
> Sent: Monday, June 13, 2016 10:10 AM
> To: amps at contesting.com
> Subject: Re: [Amps] Alpha 87a Low receive
>
>       My Alpha 86 had an Rx fuse and pin diode T/R switching.  If that fuse
> popped, my amp had exactly the same symptoms exhibited by your 87A.
> I had a pin diode failure that took out the PA's in my flex 5000.  I finally
> had enough......sent the amp off to Dick Byrd, N4UQ.  He mods the T/R board
> and eliminates the pin diodes & Rx fuse.  T/R switching is now handled
> seamlessly with a vacuum relay. No more trips or faults, the amp just works.
> Those pin diodes are the Achilles Heel of every Alpha amp that uses them
>
>      The pin diodes are still available, but they are very expensive.
>
> 73 de Bob
> N2OAM
>
> PS   I have no connection to Dick Byrd, just a very happy customer.
>
> On 6/11/2016 12:13 PM, 'DGB' wrote:
>> I recently acquired a 87A and after keying it up, the receive goes to
>> low until I hit the STBY key.
>>
>> It was reported to be fresh back from Alpha.
>>
>> What could be causing this?
>>
>> thanks 73 Dwight NS9I
>>
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