[Elecraft] K1 no power out B2

[Joe McGerald]

Well I just swapped the four band board into the questionable K1 and it
worked fine. Also I swapped one of the two questionable 2 band boards into
the working K1 and it did the same thing there, so I guess I indeed have two
non-functional 2 band boards. 

Both do the same thing -- work on Band 1 (40M on one, 30M on the other) but
don't work on TRANSMIT on Band 2. (20 and 17 respectively.) They do receive
on these bands however.

Any assistance in this mystery is gratefully appreciated.

Thanks.
Joe
AF6NI

-----Original Message-----
From: Don Wilhelm [mailto:w3fpr at embarqmail.com] 
Sent: Saturday, June 09, 2012 7:28 PM
To: Joe McGerald
Cc: elecraft at mailman.qth.net
Subject: Re: [Elecraft] K1 no power out B2

Joe,
There is no difference between the SA602 and the SA612.  They come off the
same line and  while they all conform to the better SA612 specs, some hams
are convinced that the SA602s are "better", so they label some of them '602
- You will find many ham laments about the demise of the '602. but in fact
the '612 is a direct replacement.  Use the '612.

As the prior poster has suggested, the RF board path from from P1 pin 2 to
U7 pin 4 is suspect, as is the path between P1 pin 1 ans U7 pin 5.

Yes, it is possible to have enough signal coupling to provide good receive
but not enough to give adequate pre-mixer signal input on one band.

73,
Don W3FPR

On 6/9/2012 9:18 PM, Joe McGerald wrote:
> Thanks Mike. I double checked all solder joints and components in the
area. I also checked all voltages on U7. They are correct. Guess it could be
the chip. BTW the chip is the alternate, the 612.
> Joe
>
> Mike Morrow<kk5f at earthlink.net>  wrote:
>
>
> The only path through the KFL1-2 that is not in common use for both bands
is the pre-mixer bandpass filter connections at P1/J6, where band 1 path
goes through pin 1 and band 2 path goes through pin 2.  This suggests that
you need to check the RF board from J6-pin 2 back to U7 pin 5, including the
pin on the SA602 that is plugged in at the socket.  However, this path being
open should also have degraded band 2 reception as well as transmission,
though perhaps not asy markedly.
>
> Mike / KK5F
>
> -----Original Message-----
>> From: AF6NI<astro_crazy at hotmail.com>
>> Sent: Jun 9, 2012 2:05 PM
>> To: elecraft at mailman.qth.net
>> Subject: [Elecraft] K1 no power out B2
>>
>> I just completed assembling a K1. It works fine on receive and 
>> transmits properly on B1 but not on B2.
>>
>> I have two 2 band filter boards, a 40/20 that I've had for a while 
>> and a
>> 30/17 that I just built. Both work the same in the K1. I have full 
>> power on B1, but nothing on B2. The display shows 0.1 watts but my 
>> Elecraft W1 wattmeter shows no output. As I said above, receive seems 
>> OK on both B1 and B2.
>>
>> Any suggestions gratefully accepted!
>>
>> Thanks and 73.
>> Joe
>>
>> --
>> View this message in context: 
>> http://elecraft.365791.n2.nabble.com/K1-no-power-out-B2-tp7557347.htm
>> l Sent from the Elecraft mailing list archive at Nabble.com.
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