[Moon] [Moon-net] First 23cm echoes

[w2drz]

Hi Jimmy,

Receive gain change is usually a oscillation problem with load change,
add a 3 to 6 DB pad on the preamp output then see if problem goes away..

Also are you using a RX relay that is switching the preamp to a 50 ohm
load during TX, Preamp to the relay common, with the one port to feed
and other port to 50 ohm load resistor.
 if not suggest to use that method for additional preamp protection.

On your TX problem also look for the unit to be oscillating....

tom W2DRZ


Dimitris Vitorakis wrote:
> 
> Hello all
> 
> today is a vy special day to me as i finished work with the dish and got my
> first 23cm cw echoes!
> Feed placed at the theoretical point calculated, still not aligned for
> optimum placement, tmw will do so with Sun noise.
> 
> Sun noise not yet what i should be getting but FB echoes with down to 50w at
> feed with my 3.6m dish! During echo tests i used the driver pa, with 120w at
> feed, distorted echoes peaked max at S-2 with narrow cw filter activated. I
> was amazed. Final pa works fb also. I have 3db tx line loss.
> 
> However, I have problems with my transverter which gives 4w, after a while
> 9w, and later 15w. Also, i often lose rx gain by 10db when i key down from
> tx to rx, preamp gain comes back after some minutes.
> Feed isolation is excellent, swr also and isolation of preamp seeing tx port
> of feed >65db. Sequencing works fb, so it looks to me like a relay problem
> in the transverter during tx/rx sequences. Will look into the pwr drift
> problem hopefully soon.
> 
> 73
> Jimmy SV1BTR
> 
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