1. Converting EIA from your computer to teletype current loop (so I have heard, no experience). Should also work for converting MIL +/-6v teletype signals to current loop. 

2. Building a replica of a PYTHON crypto machine
https://www.navy-radio.com/crypto/fgq1-1610-09.jpg
https://www.navy-radio.com/crypto/fgq1-1610-07.jpg



On Thu, May 25, 2023 at 9:38 AM Ray Fantini <RAFANTINI@salisbury.edu> wrote:

Please enlighten as to the possible use of the polar relay beyond land line circuits? Cathode keying replaced mechanical devices in TU by the late forties and early fifties, not being contrary and know that the polar relay has been around for a long time but have no idea why it would be used or for what? My best assumption would be that they were used to allow week currents that were on land lines to key the high current loops on the teletype printers and allow the high current loops on keyboards and perf systems to produce low current for distribution over land lines?

 

Ray F/KA3EKH

 

From: mrca-bounces@mailman.qth.net <mrca-bounces@mailman.qth.net> On Behalf Of B. Smith
Sent: Wednesday, May 24, 2023 11:00 PM
To: mrca@mailman.qth.net
Subject: Re: [MRCA] Mystery Project

 

 

KM4V is correct and a tip of the Hatlo hat to him. The relay is adjusted for "Equal Time" on the pulses with equal time displayed as center on the meter. The relay has numerous adjustments and the alignment procedure is fairly complicated but most relays just need minor adjustment unless they have been Ham Hacked.   Polar Relays and their circuits are PFM.

On 5/24/2023 3:58 PM, highpwr@bellsouth.net wrote:

Polar relay test and alignment / RTTY testing.

 

KM4V

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