[TenTec] 546c advice

[Dr. Gerald N. Johnson]

On Wed, 2008-09-17 at 21:21 +0000, jones_winston at bellsouth.net wrote:
>  
> I also once owned an Omni A (analog) and the later Omni C. Both are great rigs.
> 
> 
> However, there was a design problem in the Omni C on 17 meters that was due to the conversion scheme used.  I've heard it explained better by some engineer-type hams than I can do. I understand it caused spurs to be transmitted.
> 
17 Meters is 18 MHz. The IF is 9 MHz. The mixing scheme in that vintage
Omni mixed the PTO to 9 MHz. Mixers put out lots of second harmonic,
especially from the LO input. It probably was stronger than the mixed
signal. Hence a continuous transmitter spur. Also should show up on
receive when tuned to 18.0 MHz.
> 
> 73,
> Winston K4CWQ
> 
73, Jerry, K0CQ