[GreenKeys] Seeking patch panel with loop supply

[Nick England]

OK, what I know about TTY loops is from how the Navy ran things. Ships and
shore stations typically had anywhere from 6 to 48 loops with bunches of
reperfs and printers. They engineered a system to work reliably 24/7/365.
So that’s what I have replicated in my basement. I can patch any machine to
any TU.

The “small” patch panel SB-1203 has 6 loops, each with up to 4 devices plus
TU in series. One 1-amp 120vdc supply runs all 6 loops for one or two patch
panels. Each loop has a rheostat so you can adjust it to 60ma.
Larger 24-loop patch panels have connections for two 1-amp supplies.

If you don’t have Navy equipment it isn’t hard to make an equivalent system
with jacks and a power supply.
https://www.navy-radio.com/rtty-patch.htm

https://www.navy-radio.com/tty-loop.htm

Nick England K4NYW
www.navy-radio.com


On Mon, Sep 23, 2024 at 8:15 PM Nick England <navy.radio at gmail.com> wrote:

> I don’t understand. It’s a 60ma current loop. If you set the loop current
> to 60ma, every device gets 60ma. It is 60ma whether one device or three. It
> takes the same power whether one device or three. Period.
>
> A 120vdc loop supply and 1800 ohms or so will run a loop with TU, reperf,
> and printer no problem unless you’ve got some extra unnecessary resistance
> somewhere. I run that all the time with no problem. Maybe you need to
> adjust the KSR rangefinder because of extra inductance from the reperf
> causing some signal distortion?
> What am I missing here?
>
> I’ve got a whole bunch of machines in 24 separate loops running off two
> 1-amp supplies.
> https://www.navy-radio.com/misc/shack2/IMG_4828.JPG
> Each loop is just 120v, 60ma.
>
> Nick England K4NYW
> www.navy-radio.com
>
>
> On Mon, Sep 23, 2024 at 6:35 PM Anthony Watson via GreenKeys <
> greenkeys at mailman.qth.net> wrote:
>
>> Does anyone know if patch panels with loop current are still around or
>> are they unobtainium??? Or, maybe  a modern-ish-component schematic exists
>> to make one?
>>
>> Would like to take a signal from my one loop source and propagate it to
>> multiple machines - not enough juice in the one supply I have to power a
>> useful daisy chain loop. Hence a patch panel that powers itself might be
>> just the ticket.
>>
>> At least trying to boost the Rx loop, the KSR selectors, reperf
>> selectors, and motor shutoff control are just too hungry all at once.
>>
>> I made a switch box and employed some VRs to conserve the loop power I
>> have to go around and manually isolate the loop to the machines I’m using
>> That got me to reliable copy, which that’s not terrible but also not great,
>> and still not enough to be reliable. The motor control seems to need a bit
>> more than I got to trigger the relay.
>>
>> Anthony
>> WB7PZZ
>> WatsonAC at aol.com
>> Sent from my iPhone
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