WWII TG-5 telegraph with prices

US WWII telegraph TG-5.  

See lower part of page for recent selling prices.

This telegraph has a 1khz hum, or tone, not a clatter, as railroad telegraphs do. The technical manual, TM11-351 can be found online.

If you are doing an exhibit of telegraphy, see my telegraphy/Morse code page for suggestions: https://sites.google.com/site/scr625/telegraphy-for-children

A note on Morse code: The military and most of the world used International Morse code, which was adopted in 1912. There was American Morse code too, which was the original Morse Code, which the US railroads and Western Union used. See my webpage listed above, for the difference.

The telegraph in general had a distinct advantage over voice communication. Whereas a telephone operated with a fixed voltage, the voltage of telegraphs such as this one could be increased to compensate for poor wires or a longer distance. Second, interference had less effect on a (digital) telegraph signal than on (analog) voice communication. Though a telegraph needs trained operators to use, any foreign enemy listening in needs someone who speaks the language and knows Morse code.

The TG-5 telegraph has an interesting feature - In normal use a tone is heard in the headset; if the headset jack is removed from the plug, the bell rings in place of the headset tone.

Mine is functional, and it does have a tone when the key is pressed, and the bell rings if the headset is not plugged in, which is as good as I need for demonstrations. Powered by two 1.5 volt batteries in series, and two 9 volt batteries in series. I use battery holders and electrical tape to make a battery pack, and add a double section switch to turn the power on and off. To clean any contacts, do a few light swipes of 800 grit or finer sandpaper.

The telegraph L1,L2 output is a switching 0 to 5V DC, open circuit, which may be dependent on battery voltage. A 1.5 volt input at the L1,L2 terminals will not cause it to hum, but 9 volts will. The R-3 headset has a DC resistance of 45 ohms. If you have one without the R-3 or R-18 headset, a WWII HS-30 headset will work, if it has the longer PL-55 1.25 inch plug, not the PL-54 .75 inch plug the SCR-625 HS-30s use. The tone is loud to the ear with the R-3 headset, but less so with the HS-30 headset. I recommend using the earpiece on your head,as it is too loud to put on your ear. Some TG-5 telegraphs will have a R-18 receiver/headset which is suitable.

Test or Demo mode:

1. With -18 volts, -3 volts and positive ground hooked up to the power inputs, install a short wire at the L1,L2 terminals. Depressing the telegraph key should produce a tone. With the headset plug removed and the key depressed, the bell should ring.

2. If the short at the L1,L2 input/output terminals is removed, and 9 volts DC applied to the L1,L2 input/output terminals, a tone should be heard if the headset is plugged in, or the bell should ring if the headset is not plugged in. This simulates an incoming signal.

Feb 2019 - "test mode" in the manual says use a wire between L1 and L2, but if you are doing a working exhibit, I would suggest a 2K ohm resistor between L1 and L2, to reduce overloading the circuitry.

Always remove "D" cell batteries from any equipment not being used - they frequently leak and corrode equipment.

My first TG-5, purchased on ebay, with no bag, for $100. Be sure the headset is included. This one had no description, but excellent pictures of the good parts. However there were no pictures of the rusted battery compartment, or any note of it. When buying on ebay, let the buyer beware. Many of the TG-5s on ebay are missing the headset.  If you have one without a headset, look for a single earpiece headset on ebay. Look to see if the door support arm on the left side, by the key, is broken or not.

Warning! A number of TG-5s I've seen on ebay have had parts stripped off them. I had bid on one, and didn't notice until after I bid that the bell was missing. Luckily (for me), I was out-bid. I saw one on ebay, that was missing the relay (black item, top left, with adjustment), but the seller lists it in HUGE text that the telegraph is unused. If that piece is missing, I guess it would be unused, for certain. Let the buyer beware.

Another ebay shyster - a TG-5 for sale, and they did not have any pictures of the front open. Looking closely at the picture, there are screws missing for the telegraph key and the latch, and rust on the lower corner. The only description of condition is "Good shape for it's age". How many other parts are missing, too? Always look over a unit carefully, looking for missing parts, extra wires or disconnected wires.

Some of what has sold on ebay. I usually watch the ones that are likely to sell, or that have bids, but I don't watch everything. The ebay Buy It Now units' price may not be correct, because of the way they do things.

Oct - 2024 - A TG-5 in fair condition, with headset, no bag, sells for $150.

Oct 2024 - A TG-5 in very good condition, with headset, no bag, sells for $200.

Oct 2024 - A TG-5 in very good condition, with headset and bag, sells for $240.

Nov 2024 - A TG-5 in very good condition, no headset or bag, sells for $175.

Dec 2024 - A TG-5 in good condition, with headset, no bag, sells for $100.

Feb 2025 - A TG-5 in very good condition, with headset and bag, sells for $300?

Feb 2025 - A TG-5 missing key and headset, with bag, sells for $130.

Mar 2025 - A TG-5 headset (only), no plug, sells for $36, free shipping.

Mar 2025  - A TG-5 in good condition, with headset, no bag, sells for $149, with free shipping.

Apr 2025  - A TG-5 in very good condition, with headset, no bag, sells for $120?

Jun 2025 - A TG-5 in very good condition, no headset or bag, sells for $170.

Jun 2025 - A TG-5 in good condition, no headset or bag, sells for $109.

Jun 2025 - Two TG-5 in good condition, one headset, no bags, sell for $300.

Jul 2025 - A TG-5 in excellent condition, with bag and headset, free shipping, sells for $125.

Jul 2025  - A TG-5 in very good condition, with bag and headset, sells for $150. 

Aug 2025 - A TG-5 in very good condition, with bag and headset, sells for $206.

Aug 2025 - A TG-5 in very good condition, with bag and headset, sells for $104.

Sep 2025 - A TG-5 in poor condition, no bag,headset or key, sells for$102.

Oct 2025 - A TG-5 in very good condition, with bag and headset, sells for $320.

March 2018 -  The two TG-5s I just bought - $125 combined for both, with bags and headsets - I was the only bidder. Many people may have missed it because of a spelling error in the title. It was listed as a TG-5 teltgraph, instead of telegraph. I rarely search by "TG-5" as I did this time, usually just for "telegraph". If you are searching for a telegraph, you might try searching for "Morse", too. I have seen people list a telegraph as a "Morse code machine". As older units, I noticed that both have black headbands and black cords. The identification plate has more detail than later units, too.

1938 telegraph - After cleaning connections, it still was not working. The BK-7 relay adjustment was too tight, where there was no gap between the normally open contacts. The adjustment at the end of the relay fixed that, the bell needed adjustment, and the unit is now working.

1942 telegraph - After cleaning contacts, it still was not functional. The BK-7 relay needed the gap adjusted like the other unit, but still no output. I found the leaf spring under the key is an electrical contact, too, which needed cleaning. The BZ-7 interrupter now hums when power is applied, and the relay clicks when the key is pressed, but there is still no tone in the headset. The headset itself tests good.

Fixed! The BK-7 relay was bad, and that is the only unique TG-5 part that I have on hand, which I have replaced.

Feb 2019 - Some voltage measurements I took with an oscilloscope, with -18 volts in place of -22 supply: with 1K ohm resistor across L1, L2, there is a 4 volt peak to peak voltage at L1, L2, with a 1.5K ohm resistor at L1, L2 the p-p voltage is 5 volts. The headset voltage is about 5 volts p-p when a tone is present.

July 2019 - Some current measurements taken: test conditions - 18v and 4.3 volt (in place of 3v.) supplied, and 1K ohm load.

22v (18v actual) - .01 mA power on, 3.25 mA keyed.

3v (4.3v actual) - 4.2 mA on, 4.4 mA keyed.

Conclusion - If you use D cells for 3v. power, you could leave the telegraph on for days or more, with occasional telegraph use.

The pre-war TG-5-A modified to TG-5-B. An actual order or build date of June 28, 1938.

A 1942 model, with black headband and cord:

Technical notes:

In test mode, with headset in, the BZ-7 interrupter should hum quietly. If not, try tapping it. The L1,L2 output voltage is relative to the 22 volt supply, and the audio output is relative to the 3 volt supply. You need some very small flat head screwdrivers to do some work or adjustments.

When depressing the code key, the relay should click. If not, clean the key contacts, and see if there is a normally open gap to the right side BK-7 relay contacts.

email me if you have questions. Dewey Hassig, Minnetonka, Minnesota, USA  deweyhassig@gmail.com