SS3900 frecuency drifted on TX

[NODENS]

Good morning friends, i have a SS3900 that is receiving OK in AM (tested with another radio in same channel) but when try to transmit, i can see on frecuency counter at output is out of frecuency (near 1 Mhz more than it should have) and second radio (that works perfectly cant receive this transmission).

First thinking was could be related with VCO, but as is receiving OK, i believe that PLL is locked ok and working, so VCO must not be related with this issue. ¿How is related the TX with frecuency generation in TX ? I believe that the part that relates TX with final frecuency generation in the MIXER (IC9) is the carrier oscilator circuit around TR30.

Am i right and should look around that area, as seems i only have problem with frecuency while on tx?

Thx very much

 

[W2EKG]

VCO voltage stable? Maybe bad mixer crystal? Bad Zener?

 

[NODENS]

I will review this weekend as I'm at holiday trip. I will try to measure the freq that is out of specification at tx mixer, and then will trace back trying to see what happens with Tx freq. Thx mate I will say something if I see possible fault.

 

[NODENS]

Hi mates was resolved one crystal was dead.
Thx very much