Hello Everyone,
I’m new to this forum. I am working on a NARCO VGTR-3 transceiver and have completed the repair of the power supply section. Measured the B+ voltages and all is good. The problem now is I get a 60-cycle hum through the speaker. Any ideas on why this is or is normal for this transceiver. Thank you for your assistance.
Dave Smith
South Jordan, UT
Just a wild guess, I would say a bad filter capacitor in the power supply.
Larry – N7LUF
Thanks Larry! I do some checking in the power supply section.
OK. I’ve located the 60-cycle hum. The audio transformer is kaput. Now I need to find one of these transformers. The NARCO part number is: M-11636. If anyone out there has any information on where I can find one it would be greatly appreciated. Thank you!
Dave Smith
@homebuilt52 If you cannot find one, another option is to reconstruct it. However, it takes patience, time, perseverance and a little “manual winding machine”.
Hello all,
Ok, I measured the windings of the audio transformer and here are the measurements.
Primary: 100 ohms, secondary of first winding: 0.5 ohms (this winding goes to the speaker) secondary of second winding: 127 ohms (this winding goes to the transmitter output through the mic section.
Hello Folks,
I’m still trying to find a replacement audio transformer for this radio. If anyone knows of surplus electronics shop, I can contact that would be great. In the meantime, does anyone have a lead on a used NARCO VGTR-3A radio? I’m a volunteer at Wendover Airfield in Utah. I really want to get this project successfully completed. So, any help would be greatly appreciated.
Thanks All!