[Elecraft] K3 speaker amp chip bites the dust again

[Ross Primrose N4RP]

On 7/1/2014 4:10 PM, Joe Subich, W4TV wrote:
>
> more power, the 3.1W amplifier is going to die when asked to produce
> more than 150 W of peak power.

In a properly engineered design, the amp may clip like crazy, but it 
should be able to survive such abuse indefinitely....

73, Ross N4RP
>
> 73,
>
> ... Joe, W4TV
>
>
> On 2014-07-01 3:28 PM, Dave Hachadorian wrote:
>> I guess I've blown the speaker amp IC in my K3 again. This is the third
>> time this has happened, twice in one radio and once in another.
>>
>> In this case, the radio had both the AF Output Mod Kit (pair of 470 ohm
>> resistors) and the E85056 Audio Protection Assembly Circuit Board
>> installed.
>>
>> I was operating on Field Day, with headphones, as I usually do, when
>> some onlookers wanted to hear what was going on. I flipped
>> SPKRS+PHONES=YES, then along came a strong signal, and poof! no speaker
>> audio.
>>
>> AGC SLP was zero, and AGC THR was 020. Front panel AGC was FAST.
>>
>> This failure is really getting old, especially at $120 a pop to get it
>> fixed.
>>
>> Dave Hachadorian, K6LL
>> Big Bear Lake, CA
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> .
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to lists at subich.com
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to n4rp at n4rp.com


-- 
FCC Section 97.313(a) “At all times, an amateur station must use the minimum transmitter power necessary to carry out the desired communications.”