Lafayette Dyna-com 23 schematic

[danmcclain]

Dan: thank you very much for posting the pdf of the remainder of the info on the Dyna-Com 23. I hope the odd ball final transistors are good, 2SCF6 and 2SCF8. Never came across JP transistors with such a short number.
P

Glad I could help, good luck with the repair... Dan

 

[sunbulls]

My enhanced version of the schematic plus service manual for the Lafayette Dyna-Com 23.

 

[nomadradio]

I remember those part numbers. Never did figure out who made them. Pretty sure we used a 2SC1239 for the F8. Don't remember the F6. Probably used a baggie part like ECG or NTE back in the day.

73

 

[sunbulls]

Back in those days my transistor replacement part source almost totally relied on ECG or working pulls. ECG195A for F6 and ECG237 for F8. I found the T0-5 case style final in a Johnson 123a will work, provided that you have the T0-5 to T0-39 mounting conversion hardware.

 

[SuperLid]

Back in those days my transistor replacement part source almost totally relied on ECG or working pulls. ECG195A for F6 and ECG237 for F8. I found the T0-5 case style final in a Johnson 123a will work, provided that you have the T0-5 to T0-39 mounting conversion hardware.

2SC777 and 2SC775 come to mind

 

[epkoncept]

so excited over the past few days, I forgot to provide an update.
The Dyna-Com 23 arrived on Wed. The 3" loudspeaker was blown open. Interestingly, testing with a Megger set to 250V managed to bring the resistance down from 10's of meg ohms to about 1000's ohms. I then put about 10mA of DC through the coil repeatedly. This brought the resistance down to about 130 ohms. The loudspeaker has been working consistently as a speaker but not as a microphone. I then wired in a electret microphone as the mic. Its afixed to the rear of the speaker in a rubber grommet. Seems to work fine. TX on all 23 ch is fine. However RX on half of the channels is dead. It seems that the 11.715MHz xtal was dead. I removed it, cut the vinyl wrap of the xtal, removed it, then heated the body with my soldering iron. Still bad. I then unsoldered the xtal top half from the base. Internally it looked fine, xtal not broken and wires were still attached. I then tested it and it worked. I guess the conductive glue wasn't connecting between the leads and the quartz wafer, but the high heat of unsoldering the can fixed it. It seems to work reliably for the past couple of days. So happy. Compared the RX to another walkie talkie and it seems reasonably similar. But the max audio level is lower than Dyna-Com 5. receiver quieting is about the same. May be this is just due to the bad loudspeaker. I don't have a 2 3/4" 100 ohm speaker to test. Also I don't have any 100 to 8 ohm miniature audio transformers.

P