[TenTec] 2.8khz and Carrier Balance???

[Ken Brown]

Steve N4LQ wrote:

> Would someone please explain to me what changing the filter from 
> 2.4khz to 2.8khz has to do with carrier balance.
> I see no relation. The carrier is nulled by balancing the dc voltage 
> on U4 of the TX Audio board. No filter is anywhere near there. U4 
> feeds DSB into the 9mhz filter but the carrier must be nulled before 
> it gets there so whats going on with all this carrier balance talk I 
> keep reading about????? 

Since the DSB output of the balanced modulator goes to the 2.4 or 2.8 
kHz filter, changing the filter could possibly change the loading on the 
balanced modulator, requiring readjustment for best carrier null. I 
think that difference in filter loading on the balanced modulator is 
rather unlikely to make a significant difference. However since the 
filter is wider, and the point of this modification is to improve audio 
fidelity, lower frequency audio sidebands AND the carrier will be 
attenuated less by the wider filter. So  in order to acheive the same 
carrier supression as with the narrower filter, the carrier null has to 
be adjusted more precisely.

DE N6KB