[1000mp] Field Model Clicks And Thumps In The Headphones Cured

[Dean Fewkes]

Jim,

My Field had both clicks and thumps in the headphones when operating CW 
from the time it was new. I played with the menu settings, but all that 
did was mask it a little.

The thumps can be described as a very low frequency thump (below 50 Htz) 
that is heard with every transmitted dit regardless of whether you are 
working full QSK or semi. The problem is noticed because most headphones 
have strong reproduction of these very low audio frequencies. I solved 
the thumps shortly after getting the radio by installing a 1uf 
electrolytic capacitor in line next to each headphone speaker.

This also had a slight effect on the full bodied sound that the Mark V 
produces on SSB so I installed micro switches to bypass the capacitors 
when listing to wide SSB. The switches fit nicely into my Heil Pro 
headset. I used the switches because I have always been amazed with the 
beautiful warm sound that the Mark V produces on SSB and I did not want 
to reduce this in any way. You could probably use 2.2 or 4.7uf 
capacitors as a compromise if you do not want to install the switches.

The clicks can be described as a broader spectrum click that occurs 
during full QSK or only when the radio switches from tx to rx during 
semi qsk. This is usually heard when the volume is turned up because 
signals are faint. On my radio, it was more evident with certain 
combinations of filters too. I used to minimize these clicks by keeping 
the rf gain high, and the volume low. When I recently installed the 
roofing filter, inrad key click mod and some new 2.8 Khz IF filters, the 
clicks totally went away. I think they were cured by either the roofing 
filter, key click mod, or both. Now there is no trace of the clicks in 
the headphones even if I try to hear them.

Wow, it sure is nice to have smooth QSK again, it sounds like a symphony.

Dean Fewkes
KG7MZ
Kalama, WA

_____________________________________________________________________


Jim Smith wrote:
> I'd be very interested in hearing about this
> 
> 73, Jim Smith   VE7FO
> 
> Dean Fewkes wrote:
> 
>> Hello Andy,
>>
>>
>> Do you have the clicks and thumps in the headphones too? If so, I can 
>> help you eliminate those also.
>>
>> Good Luck!
>>
>> Dean Fewkes
>> KG7MZ
>> Kalama, WA
>>
> 
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