[GreenKeys] TTY loop jack boxes - SET, LPG, MISC

[Nick England]

Oh yes one more comment about wiring your TD to the SET jack of another
channel. That would be fine. Or you could just leave the TD on a MISC jack
and jumper the SET connection on that extra channel (assuming it has a loop
supply). Then you could plug in whatever equipment you wanted to the LPG
jacks of that dummy loop.

On Sun, Aug 15, 2021 at 8:38 AM Nick England <navy.radio at gmail.com> wrote:

> Sounds like you have got it pretty much figured out.
> Usually LINE (TB-101) was connected to a keyer or converter and SET to a
> printer or reperf or TD.
>
> None of the Navy RATT/RTTY keyers, converters, or TUs had an internal loop
> supply - so the standard installation was a single loop supply that was
> used for all six channels. The default shows that.
>
> IF your TU supplies loop current, then change the strapping to REMOTE for
> that channel, maintaining polarity. See
> https://www.navy-radio.com/rtty/patch/1203a-man-05.JPG - you still hook
> up that TU to TB-101 and TB-102 is still available for SET use.
>
> A keyer or converter would be wired to the LINE terminals on TB-101. If no
> keyer or converter is used for that channel you could connect a TD, reperf,
> printer, or just a strap. BUT note that piece of equipment would always be
> connected to that channel - you could not patch it elsewhere.
>
> Some of the converters had the minus line connected to ground so that
> would be wired to TB-101/1 for example. Don't try to put one of these
> converters on a MISC jack and then plug it into a loop - it'll just short
> out the loop before it gets to the SET.
>
> Printers were often polarity sensitive so the plus lead would go to TIP.
>
> Patch cords were wired TIP-TIP and SHELL-SHELL - All 60ma loop panels used
> TS jacks and plugs.The Navy later used TRS for low-level (+/-6v) panels.
>
> I'd agree with John that putting the ROTR on a SET connection might be
> nicer so that it wouldn't run open. Otherwise put it on a MISC jack and
> leave it patched into a LPG jack on some channel.
>
> The SB-1210 version is a little more handy in that it has two SET jacks
> and two LPG jacks (and it is bright CRYPTO red)......
>
> Nick England K4NYW
> www.navy-radio.com
>
>
> On Sun, Aug 15, 2021 at 6:21 AM Paul Birkel <pbirkel at gmail.com> wrote:
>
>> So … I’m still not the “sharpest crayon in the box” on this topic.  Let
>> me use the SB-1203/UG as my example (documented online at:
>> https://www.navy-radio.com/rtty/sb1203.htm).  It has six identical
>> circuits (“channels”) – one example diagrammed at:
>> https://www.navy-radio.com/rtty/patch/1203a-man-07.JPG
>>
>>
>>
>> Inside the unit there are several sets of terminal strips (see:
>> https://www.navy-radio.com/rtty/patch/1203a-man-01.JPG) establishing
>> pairs of permanent connections corresponding to the TB-* appearing at the
>> bottom of the example schematic diagram.
>>
>>
>>
>> TB-101 would normally connect to some equipment  (this is, I think,
>> “(LINE LPG)” in the terminal strip diagram) that is _*always*_ in that
>> particular channel (examples from that terminal strip diagram are “RADIO
>> ADAPTERS, FREQUENCY SHIFT KEYERS, LINE MODULATORS”), and may optionally
>> supply loop-current, correct?
>>
>>
>>
>> Alternatively TB-101 could be strapped closed under the assumption that
>> there is a SET connected to TB-102 and there is a loop-supply established
>> via TB-104 and the default strapping?
>>
>>
>>
>> The distinction between TB-101 and TB-102 seems to be whether the SET
>> supplies loop-current or not, correct?
>>
>>
>>
>> TB-102 (SET jack) would connect to some equipment that is normally in
>> that channel, but can be either:
>>
>>
>>
>>     (1) removed from that channel by inserting some sort of “dummy” plug
>> (has no internal wiring)? … or
>>
>>
>>
>>     (2) removed from that channel and connected into some other channel
>> using a patch cord
>>
>>             that establishes a connection between two plugs where the
>> second plug is then inserted into
>>
>>             a LPG jack on another channel?
>>
>>
>>
>> TB-103 (MISC jack) would connect some equipment that is not in any
>> channel, to some channel using a patch cord  to a LPG jack?
>>
>>
>>
>> (The documentation for this unit is quite good; my comments above attempt
>> to summarize my functional understanding of how it is intended to be
>> employed as an exemplar of what I assume is a pretty standard approach to
>> loop jack boxes.)
>>
>>
>>
>> Is “patch cord” the correct terminology?  Is it just wired tip-to-tip and
>> ring-to-ring (or shell-to-shell if two-wire)?  Are they normally TRS (shell
>> left unconnected?) or TS?
>>
>>
>>
>> Now, for a use-case, if my source were a self-powered loop from a Flesher
>> TU-170 (which incorporates a loop supply and 0.125A fuse) it seems to me
>> that I’d:
>>
>>
>>
>> 1.     Strap the SB-1203/UG for REMOTE internally (rather than use the
>> default strapping for a TB-104-connected loop supply).
>>
>> 2.     Connect the TU-170 to TB-101.
>>
>> 3.     Connect a (for example) M15 to TB-102 (SET jack).
>>
>> 4.     Connect a (for example) M14 ROTR to TB-103 (MISC jack).
>>
>> 5.     Connect a (for example) M14 TD to a different TB-103 (some other
>> MISC jack)
>>
>> 6.     Optionally add a loop-cable from MISC to an JPG jack to use the
>> M14 ROTR to generate a paper tape of traffic between the TU-170 and M15.
>>
>> 7.     Optionally add a loop-cable from other-MISC to an JPG jack to use
>> the M14 TD to read a paper tape “into” traffic between the TU-170 and M15.
>>
>> 8.     Optionally add a loop-cable from SET to an JPG jack in some _
>> *other*_ channel to move the M15 to that other channel (which would need
>> to have at least loop supply established).
>>
>>
>>
>> Would this be a reasonable approach?  Would it be a _*good*_ approach if
>> these were the four items to be co-employed in this use-case :->?
>>
>>
>>
>> Would it, in fact, be better to treat the M14 TD as a SET in a different
>> (powered) loop in which case I could then either:
>>
>>
>>
>> A.    cross-connect the M15 there, or
>>
>> B.    cross-connect the M14 ROTR there, or
>>
>> C.    cross-connect the M14 TD into the TU-170 loop?
>>
>>
>>
>> This seems like a more flexible approach assuming that there is available
>> a separate loop supply for the second loop.
>>
>>
>>
>> Am I thinking about all of this “right”?  Inquiring minds want to know!
>>
>>
>>
>> Thank you,
>>
>> paul
>>
>>
>>
>> (A long message, but I’ve not gleaned enough specificity from GK traffic
>> archives.  Hopefully by being pedantic here … we’ll avoid more “dull
>> crayons” in the future :->)
>>
>>
>>
>> *From:* greenkeys-bounces at mailman.qth.net [mailto:
>> greenkeys-bounces at mailman.qth.net] *On Behalf Of *Nick England
>> *Sent:* Sunday, August 08, 2021 3:33 PM
>> *To:* Greenkeys
>> *Subject:* [GreenKeys] Fwd: TTY loop jack boxes - eBay
>>
>>
>>
>> Argghh - I forgot to include the link to my page with schematic and
>> explanation
>>
>> https://www.navy-radio.com/rtty-patch.htm
>>
>>
>>
>> In the schematic for this type of box, you will see that the LPG jacks
>> are shorted when nothing is plugged in. When nothing is plugged into the
>> SET jack, the associated equipment is in the loop. When you plug a cable
>> into into the SET jack, the equipment is taken out of the loop onto the
>> cable and the loop is shorted. This is so you can plug the equipment
>> normally in Loop 1 into Loop 2 for example and vice-versa (jumper SET-1 to
>> LPG-2 and jumper SET-2 to LPG-1).
>>
>>
>>
>> *"NOTE: Anyone patching or unpatching circuits from a TTY panel must be
>> sure to pull the plug from the looping jack (LPG) before removing the other
>> plug from the SET (machine) jack. Pulling the SET jack first interrupts all
>> TTY message traffic on that channel. IT ALSO PRODUCES A DANGEROUS DC
>> VOLTAGE ON THE EXPOSED PLUG!"*
>>
>>
>>
>>
>>
>> Nick England K4NYW
>> www.navy-radio.com
>>
>>
>>
>> --
Nick England K4NYW
www.navy-radio.com
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