UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Dave Moll · 28th May 2019, 9:54 am

I can confirm the monitor function to be available, using my telephone tester, with one of the three 704s that I have.

The one specifically labelled as a 704B, as expected, continues to make a loop with the cut-off button pressed.

The second, with no model number label, but with a sticker saying BBC, only makes a loop when the cut-off button is released.

The final (unlabelled) one doesn't have a cut-off button.

By the way, it would be a BAD idea to connect to a CB/auto exchange in LB mode, as one would be attempting to put power from the battery onto an already-powered line!

28th May 2019, 9:54 am	#42
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: "Butt" 'phone I can confirm the monitor function to be available, using my telephone tester, with one of the three 704s that I have. The one specifically labelled as a 704B, as expected, continues to make a loop with the cut-off button pressed. The second, with no model number label, but with a sticker saying BBC, only makes a loop when the cut-off button is released. The final (unlabelled) one doesn't have a cut-off button. By the way, it would be a BAD idea to connect to a CB/auto exchange in LB mode, as one would be attempting to put power from the battery onto an already-powered line! __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley) Last edited by Dave Moll; 28th May 2019 at 9:58 am. Reason: By the way...