I got a really decent TRC-490 that had it's SSB switch smashed. I was able to replace the switch and repair the knob and the radio works great. I just finished a cap replacement and it works really well. Since this radio has the MB8734 chip, I do not want to replace it and instead will go with a loop crystal mod. It uses the 11.3258 xtal. I read the radio is pretty broadbanded, so I got the xtals to go HH, H, L and LL. I got a rotary switch to fit in the phone jack, so there is no cutting or drilling and the knob blends well, looks factory.
Here is the issue: I cannot get lock on some of LL and none on HH.
I get good lock on 26.515 thru 26.955 and CB, but for H, I have to turn the radio off and on to get it to lock for 27.415 thru 27.855 although it will transmit with full 4 watts. No lock for HH crystal. For LL I get lock from 26.505 down to 26.305 and then no VCO lock. If I adjust the VCO to lock on 26.065, I lose the Highs and same issue backwards to lock the High High freqs. I can compromise and leave it like it is since I am not interested in going into 10 meter freqs.
I read here the thread on the 142GTL mod:
https://www.worldwidedx.com/threads/poormans-192-channel-mod-cobra-142-gtl.79065/
Will snipping R71 apply to this radio as well or it is limited to the MB8719 chip? Anything I should look for to get most of the freqs to lock on this rig?
Thanks in advance!
Here is the issue: I cannot get lock on some of LL and none on HH.
I get good lock on 26.515 thru 26.955 and CB, but for H, I have to turn the radio off and on to get it to lock for 27.415 thru 27.855 although it will transmit with full 4 watts. No lock for HH crystal. For LL I get lock from 26.505 down to 26.305 and then no VCO lock. If I adjust the VCO to lock on 26.065, I lose the Highs and same issue backwards to lock the High High freqs. I can compromise and leave it like it is since I am not interested in going into 10 meter freqs.
I read here the thread on the 142GTL mod:
https://www.worldwidedx.com/threads/poormans-192-channel-mod-cobra-142-gtl.79065/
Will snipping R71 apply to this radio as well or it is limited to the MB8719 chip? Anything I should look for to get most of the freqs to lock on this rig?
Thanks in advance!