Systems Saber Module Swap- No TX!!!

[RADIO43]

Guys,

Recently did a module swap in a few systems sabers. Since the swap out, the radio's RX is awesome but TX is not working. When I key up the radio, it keys up the radio for approximately a 1/2 second (TX light comes on) and then stops and I get a tone. This tone is not cause by a Secure or Clear operation because it is currently disabled. Is something out of lock? Any assistance is apperciated.

Radio43

[DJP126]

Probably the VCO. Make sure you have the proper VCO module for the frequency range of your radio. Also make sure that you didn't bend one of the pins when you swapped the module.

[RADIO43]

I actually have three radios that I converted and they are all doing the same thing. I pulled out all of the modules from the 481-512 mhz sabers and placed them on the 403 mhz board of the systems saber. I also made sure that no pins are bent, but I am still having the problem. Also, the receive is working awesome, what a hot receiver on these. I have to get them on a monitor but I know the software gives some pretty good tuning values when switching the band of the sabers. Thank you for the reply.

radio43

[RADIO43]

Okay,

I am starting to think the VCO is out of lock. Where is the adjustment for the VCO. I can not find it in my tuning values, nor can adjusting my tuning setting, fix this. Any help on this wouyld be awesome.


Radio43

[DJP126]

IIRC the only "tuning values" that the VCO has is selected by the radio range info. Since you are selecting range 4 (482 - 512 MHz), make sure the VCO part number is NLE9464.

[RADIO43]

Dave,

Thank you for the help. That is the VCO module that I have in there. The amazing thing here is that the radio's receiver is red hot... I will play around more.

Radio43

[DJP126]

The VCO has two circuits, one for tx and one for rx. Therefore you can have good rx and no tx, good tx and no rx or (if the common circuits are bad) no tx and no rx.

[RADIO43]

Dave,

Thank you again. The only thing is that all three radios are doing the same thing. Is it possible that something happened when I was installing all 3? Also, these modules came out of working, perfect condition 482-512 sabers.


Kyle

[RADIO43]

Guys,


Here is a question. Should I have changed the reference crystal/reference oscillator between the radios? When changing boards I also changed these. I am starting to think this is my problem. Any help would be awesome.


Radio43

[RADIO43]

Changed that back and still getting same results... Damn... I was thinking that was it.... I will keep trying.... radio43

[DJP126]

Try checking the next tx stages. The RF amp and the FDS. Once again, make sure there are no bent pins on these. Also, since the modules came out of working Sabers and you put them into System Saber boards, are you sure the System Saber boards are good?

[RADIO43]

Dave,

The 403-433 mhz Systems Sabers were all in working condition before boards were changed out. I will check all the pins again and see if any are bent. The amazing thing about this is that the receive on these things are awesome. An interesting fact here is that when hitting the TX Button, the radio TX'ies for about a 1/2 second and then stops.


Thank you again for the help.

radio43

[DJP126]

A couple of other possibilities.
Are the screws on the rear shield tha go into the VCO tightened down (to two inch pounds MAX)?
Could the rear shield be shorting out through a worn insulator?