[TenTec] Omni 6 Plus: No RX or TX on 10 meters (Intermittent)

[Steve Berg]

Back in the late 1970s and early 1980s, I worked on Motorola IMTS 
synthesized car phone radios.  This was before plated through holes in 
PC boards were reliable.  So, the Big M used eyelets, instead. The 
solder in these would crystalize and the synthesizer would be producing 
all sorts of wrong frequencies.  I made a decent living resoldering many 
of these boards for some years.

73,

Steve WA9JML


On 7/6/2015 7:46 AM, Jim Allen wrote:
> I'm glad you found the fix.
>
> Why is it there are so many re-solder fixes these days.  I don't recall ever hearing about resoldering on the old gear.  Anybody ever have to fix a 75A4 or SX101, etc. by resoldering some connections?
>
> 73 de W6OGC Jim Allen
>
> Sent from my iPad
>
>> On Jul 6, 2015, at 7:39 AM, Joe Papworth via TenTec <tentec at contesting.com> wrote:
>>
>> It appears to be fixed and in repairing it, I fixed another annoying problem, which was spurs and floaters on ten meters only. Those had been plaguing me for several years.
>>
>>
>> First, thanks to Paul at Ten Tec for pointing me in the right direction and to Mark, K8VF, and others for their suggestions.
>>
>>
>> Paul was right. The problem was on the Xtal Osc/LO board. The repair process went like this:
>>
>>
>> 1) I looked at the schematic of the board and saw there are 4 separate xtal
>> ? ? oscillators for ten meters (I assume one for each 500 Khz band segment)
>> ? ? Since I was losing the entire band, I knew it wasn't one of those circuits.?
>> ? ? That eliminated a lot of circuitry as a possible cause.
>>
>>
>> 2) After reading the theory of operation, I pretty much narrowed things down ? ? to the L9, L10, and L11 circuits, plus the Q4 and Q5 circuits.
>>
>>
>> 3) I resoldered every component in those areas and voila, no more spurs or
>> ? ? floaters and so far, RX and TX are fine. (I'm fairly certain the rig would
>> ? ? have failed?by?now)
>>
>>
>> Later, Joe
>>
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