[Heathkit] SB-220 Problem

[jeremy-ca]

There is an open circuit (denergized) in both amp relays when in receive. 
Dirty RX contacts or contacts welded in TX are possibilities.

Easy enough to Ohm the path to find the problem.

Polarity makes no difference as long as the xcvr relay can switch ~125VDC @ 
100 ma. for transmit.

Carl
KM1H

----- Original Message ----- 
From: "Mike McCarthy, W1NR" <lists at w1nr.net>
To: "Larry Boekeloo" <lboekeloo at sbcglobal.net>
Cc: <heathkit at mailman.qth.net>
Sent: Tuesday, December 18, 2007 12:03 PM
Subject: Re: [Heathkit] SB-220 Problem


> The SB-200 and 220 have reversed polarity on the antenna relay connection. 
> I think the 200 is negative and the 220 is positive.  There could also be 
> a bad connection on the RX side of the relay as well.  See what happens 
> with the relay disconnected to determine if it is a polarity issue.  Then 
> try burnishing the contacts of the relay to see if it receives any better.
>
> Mike, W1NR
>
>
> Larry Boekeloo wrote:
>> I purchased an SB-220 a few months ago and just got around to hooking it 
>> up last night.  I installed it in place of my SB-200 with the same 
>> cables, etc.  When I power the transceiver up, I have no receive.  It 
>> acts as though the antenna connection in the SB-220 is to ground.  Anyone 
>> else experience this or know where I should look before I tear into this?
>>    Thanks.
>>    KN8N
>>
>>
>