I have a FOUR wire D104 from 1975 I am trying to wire to a Royce 1-621. When wired according to every diagram I have found 1- White 2- Shield 3- Red 4- Black, it screeches from the speaker. Keyed up it is fine, good modulation but as soon as I unkey it squeals like a stuck pig from the speaker. If I unsolder the audio wire from the plug, receive is fine and can transmit but, of course no modulation. I am pulling my hair out trying to figure this one out :headbang.
Thanks to anyone that can help,
bluestreak (383 windy city)
Thanks to anyone that can help,
bluestreak (383 windy city)