D37 Maxtrac wont TX on certian frequencies

w2rac · Post by **w2rac** » Sat Feb 17, 2007 4:24 am

I have seen a related post but no definitive answer.
My D37 Maxtrac, a former trunking radio, converted to conventional, wont transmit between 906 to 908.
The radio is programmed ok with RSS 7. I even tried Lab v5 (this has a hard time reading and writing the radio) and still the radio simply wont TX.

Any ideas, suggestions, places to read more?

Thanks
W2RAC

Post by **xmo** » Sat Feb 17, 2007 7:17 am

Did you do the appropriate VCO mod?

If so - revisit that. Check your steering line voltage for frequencies that work and those that don't. Also check to see which VCO section is active when the radio transmits OK vs. when it does not.

w2rac · Post by **w2rac** » Sat Feb 17, 2007 8:58 am

Thanks, I will try this and get back with the results.

xmo wrote:Did you do the appropriate VCO mod?

If so - revisit that. Check your steering line voltage for frequencies that work and those that don't. Also check to see which VCO section is active when the radio transmits OK vs. when it does not.

w2rac · Post by **w2rac** » Sun Feb 18, 2007 4:45 pm

OK, the VCO is opened up and I notice this
TX RX SL RX TX voltage
902.5 902.5 .64 7.9
906.5 906.5 .64 .64 (no TX)
927.5 927.5 2.8 2.8
907.3 919.3 .7 .64 (no TX)
902.65 927.65 2.94 7.9

Looks like I need to readjust the striplines to allow the greater TX freq??
Or does supplying a constant voltage be the better cure?