[GreenKeys] TU-170 with External Loop Supply
John, W9DDD
w9ddd at tapr.org
Mon Aug 16 08:03:49 EDT 2021
Well I remembered to look, but I couldn't remember where!
In the meantime here's a snippet from a poor scan that appears on
ElektroTanya.com. Actually in terms of showing the ground connection
for the transformer's CTs, it's a better scan.
You'll notice that R74 is present instead of the fuse, indicating this
is from an earlier kit.
---
----
The above comments or recommendations are SWAG. Use at your own risk.
John, W9DDD
On 8/16/2021 4:48 AM, John W9DDD wrote:
> I think the center tap to ground symbol connection has suffered the
> same fate as the connection between R60 and M. I will go fetch my
> hard copy later (if I remember) and see if it's any clearer. Some
> times a faint line will disappear in scan.
>
> John, W9DDD
>
>
> On Aug 16, 2021, at 3:37 AM, Paul Birkel <pbirkel at gmail.com
> <mailto:pbirkel at gmail.com>> wrote:
>
>> Daniel: [U] (TIP) now being disconnected (fuse removed) the wire-pair
>> would be between [R] and what? [R] would be TIP? I’m not yet
>> envisioning the revised circuit and how it would work with an
>> external supply.
>>
>> (The published schematic for the TU-170 itself appears to be in error
>> as the center-tap on the secondary of T1 and T2 isn’t indicated as
>> being connected to chassis GND.)
>>
>> *From:*Daniel Jones [mailto:djones at k6yic.com]
>> *Sent:* Sunday, August 15, 2021 10:56 AM
>> *To:* John W9DDD
>> *Cc:* Paul Birkel; Greenkeys
>> *Subject:* Re: [GreenKeys] TTY loop jack boxes - SET, LPG, MISC
>>
>> I forgot to mention that I did remove C40 which couples the collector
>> to chassis ground.
>>
>> I removed the loop jack on the back and run a pair of wires in its
>> place without C40.
>>
>> (Side note if you have an older version only the TU-170 you might not
>> have a loop fuse but a resistor in its place (R74), this would need
>> to be removed to accomplish the same thing. I have both types).
>>
>> I have mine patched into my 1203a panel using a Navy PP-3494A/UG loop
>> supply to make everything work.
>>
>> Also as a note I don’t believe that the meter will work or the
>> current adjustments will be functional if you don’t have an external
>> supply. It’s not necessary but diminishes the cool factor a bit in
>> my opinion.
>>
>> Daniel
>>
>> Sent from my iPhone
>>
>>
>>
>> On Aug 15, 2021, at 07:26, John W9DDD <w9ddd at tapr.org
>> <mailto:w9ddd at tapr.org>> wrote:
>>
>>
>>
>> How are you handling the fact that the emitter of the switching
>> transistor of the TU-170 is pretty much at circuit common.
>>
>> John, W9DDD
>>
>>
>> On Aug 15, 2021, at 7:43 AM, Daniel Jones <djones at k6yic.com
>> <mailto:djones at k6yic.com>> wrote:
>>
>> Nick pretty much explained it but I will mention that I use a
>> TU-170 connected to my 1203 but I utilize an external loop
>> supply.
>>
>> I just pulled the loop fuse on the TU-170 and it now just
>> utilizes the same external power supply that my other
>> Terminal units require (CV-2460 adn CV-483). It has been
>> operating fine forte last 5 or so months being on all
>> weekend. The nice thing about the 1203 is the fact you can
>> adjust the loop current for each channel.
>>
>> My 2 cents….
>>
>> Daniel Jones (K6YIC)
>> DJones at k6yic.com <mailto:DJones at k6yic.com>
>> http://K6YIC.com
>>
>> HH Phone #11973
>>
>>
>>
>> <logo-globe-600dpi.jpg>
>>
>>
>>
>> On Aug 15, 2021, at 3:21 AM, Paul Birkel <pbirkel at gmail.com
>> <mailto: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>[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, theassociated
>> equipmentis 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 <http://www.navy-radio.com/>
>>
>>
>
>
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
>>>> Jordan Spencer Cunningham's GreenKeys Search Tool: https://teletype.net/gksearch
>>>> 2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/
>>>> 1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html
>>>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to w9ddd at tapr.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20210816/ecfe3912/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: icedcnphbddfhbef.png
Type: image/png
Size: 55527 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20210816/ecfe3912/attachment.png>
More information about the GreenKeys
mailing list