Gross Transmitter - Needed Info - All Set and Tnx!

[W1UJR]

Hi guys and gals,

This weekend a nice replica Gross transmitter landed on my doorstep, a gift from a fellow Antique Wireless Association friend.
It was built some time ago, and been sitting since the passing of the owner.

I could use some assistance on the following:

1) Schematic for the unit and actual ID of the model. BAMA does not have, and I am not certain of the Gross model it was patterned after. It is a CW only rig, and the unit currently has a pair of Taylor TZ-40 tubes in the output, but I understand that it used to have TZ-20s. Perhaps that will provide a clue. I've also included a photo of the unit below.

2) A Taylor 866 Jr tube. One of the 866 Jr has broken away from its base, and appears to be internally disconnected. Any one have a spare 866 Jr laying about?

3) Black crackle refinishing. I know that this has been discussed before, but does anyone have a good source for stripping and professional refinishing in black crackle/wrinkle paint? This unit was originally sprayed with the aerosol can form, and its really starting to come off. I'd prefer to do this correctly and disassemble the unit so it can be professionally refinished.

4) I've placed a list of needed parts on the link below, please contact me if you can help.

Thank in advance!

73 Bruce W1UJR


Link to "Bruce's Bench" --> http://www.w1ujr.net/bruces_bench.htm

Link to list of Parts Needed --> http://www.w1ujr.net/gross_tx_restoration.htm


Overview of unit

[KA8WTK]

Hi Bruce,
  Looks like it could be a Gross CP-55 that has had a new power supply built and placed in the bottom. Take a look at the picture below.

Bill KA8WTK

[Pete, WA2CWA]

Unfortunately, the pictures are too dark (takes forever to load) and the pictures are so close in, it's difficult to get a feel as to its real looks. If you looking for identification, lighting the tubes is really not important. But, based on what I'm seeing, it's probably patterned after the CP-55 which has a CW-55 RF unit and P. S., or the CP-100 which has a CW-100 RF unit and P.S. What's the tube lineup in the RF unit and give us a photo of the complete unit without us having to scroll up and down and left and right to view the entire unit.

[W1UJR]

Hey Pete, since corrected.
I did not realize they appeared that large, check the new image.

Tnx - Bruce

[Pete, WA2CWA]

Great! Much better photo and I stand by my last post; CP-100 or CP-55 depending on the tube lineup in the RF deck.

[WU2D]

Wow Bruce,

That transmitter is an AWA prize winner if it has a story behind it. Can't wait to hear it's voice.

It looks to be 1930ish.

I tried to get something out of the pictures in photoshop.

It is similar looking to the AERO reproduction that I made a couple of years ago. I still have to add the mod section to the AERO (right now it is TPTG with CW only).

Mike WU2D

[W1UJR]

Mike, I'd love to see some photos of your Aero unit, if you feel like emailing over. :-)

Thanks guys, and I agree it looks like a CW-55, but this one has additional tubes and transformers on the power supply deck. I suspect that is just John's handiwork or provisions which he made as the exact original parts were not available.

For testing purposes, I'd dearly love to get my hands on a schematic of the "55", then I could reverse engineer it to include the differences on this one. So if you know if any place or person who has one, please to let me know. John said he would try to draft one up, but its been some time since he built the unit.

The biggest challenge is that I can't fire this up yet as one of the 866 Jr tubes has a loose base and apparently broken wires in the pins. I plan to dissect that tomorrow evening and see if I can repair. The 866 Jr is different that the standard 866 in that no plate cap is used, so I can't just plug in a good old 866. I could solid state the supply, but that somehow seems wrong.

In the meantime, I have fired up the VFO, also a nice homebrew piece by John. I assume the VFO was built for practical use, while the xtal can be use to be "authentic". The xtal socket is still on the RF deck, takes the large cased Gross xtal, just in case one wants to operate that way.

I'll post progress and updates on the unit as time goes by.
I appreciate any suggestions you might have in terms of locating the needed parts and schematic.


73 es Best to all for the new week,
Bruce W1UJR

[AB3L]

Howard Mills does tons of St. James Gray powdercoat. It is a tighter wrinkle like the original Collins black boxes.

[W1UJR]

Well guys (and gals), I managed to get the beast fired up and on the air.

She is making RF, about 25 watts out of the TZ-40s, when loaded moderatly.
Not strapping, but plenty 'nough on CW to make contacts.
The loading really effects the tone, sure not T9X, but thats OK, part of the charm.

My sincere thanks to those who helped, that's the great thing about AM Fone.


73 Bruce '1UJR

Photo below of station, if you look carefully you can just see my 60 watt light bulb dummy load.
Yes, Electric Radio coffee cup was standard  back in '39. 

[AF9J]

Good Morning Bruce,

Cool setup - the Gross transmitter, and an HRO receiver.  The blue glow of 866 mercury vapor rectifiers.  Not very efficient - but very cool to look at!  Now just hook up a bug, and you're all set to go.  Does it do 160?

73,
Ellen - AF9J

[W1UJR]

Tnx for the kind comments.

Yes, I love those 866s, nothing pretty than to watch as they flicker during keying.

No 160 yet, but I'd like to wind coils for that band, as well as 40 meters.

Yes, I need to get rid of that chrome Bencher key, was just most convenient at the time.

I just picked up a Vibroplex Zephyr last night Ellen, should be next week.
That was a key which I wanted for while, and although not the correct time period for this station, it looks nice.

[AF9J]

Niiice!!  I have a Bencher RJ-1 straight key.  It works pretty good, as long as you don't do european style sending, which makes it's undersized base rock back and forth.  I've had it since '96, when I bought it from AES, so I'd have a straight key for SKN.  Your Zephyr is basically similar to my Champion Bug.  After foolishly selling off the Lightning Bug I'd owned last year (which I'd bought new in 1982), I won it on ePay for $48 (the base was refinished in very light gray, which made it undesirable to collectors).  As I mentioned in another thread, you can get them at 80-90% of what you want pretty quickly, but getting that last 10-20% is a bugaboo.  My Lighting bug was tweaked to the max.  After using it a lot yesterday (and making additional adjustments), it's better, but it still is off by about 5% or so of what I want.  BTW, nice looking Zephyr Bug.

73,
Ellen - AF9J

[k4kyv]

What is the difference between European style sending and American (or Asian, African or Australian) sending?

But I don't send with a straight key or electronic keyer.  I much prefer my velvet-smooth 1929 vibroplex bug.  I also have a 1947 vintage vibroplex, but the thing really sucks, with loads of contact bounce and an overly stiff feel.  I have noticed the same thing with the new vibroplexes made at the factory in Alabama.

[AF9J]

Hi Don,

OK, here I go.  In American style straight key sending, you rest your forearm on the table, and use wrist action to work the key.  In European style sending, you don't rest your forerm on the table.  You also keep your wrist stiff, and use forearm action to work the key.  It's kind of like guitar playing.  Some players rest forearms on the guitar body, and just strum or pick by moving their wrists.  Other players move their arms to strum a guitar. 

It threw me for a loop, when I heard about European, and American style sending, for the first time last year, right after I joined SKCC.  The styles are derived from the way American and European landline telegraphers used to send.  If you ever take a look at a American, or European straight keys you will notice that they are physically different from each other, to accomodate the two different sending styles.  American keys like the the J-38, and the Vibroplex straight keys, have a curved lever that puts the end knob low to the table, which is more comfortable for wrist action sending.  European keys have a straighter lever, that puts the end knob up quite a bit higher above the table, which gives more leverage, and provides more clearance for arm movement.  Because European style sending is more physical, european style keys are typically larger and heavier, to keep them from moving around, when you send.  You can use an American key for euro-style sending, but euro keys aren't very comfortable for american style sending, because they place your wrist & forearm too high off of the table.

Here are some links to photos that illustrate what I mean.

American style key by Nye Viking - notice the curved lever arm:

http://www.mtechnologies.com/nye/nye312.jpg

European style key by Kent, an English company - notice the chunky, higher elevated arm:

http://www.kent-engineers.com/titanicinfo.htm

73,
Ellen - AF9J
SKCC # 1369

[Rick K5IAR]

Wow!  I guess we never stop learning.  I did not know these facts either, Ellen, thanks for the education. 

....who said you can't teach an old dog new tricks?

Rick/K5IAR

[AF9J]

You should see some of the really hefty old school euro keys.  They literally live up to the slang term of "pump" used for a straight key:

Here's a Danish Amplidan, foir shipboard use:

 http://www.mtechnologies.com/amplidan/713b.jpg

A Swedish Soxman: http://www.mtechnologies.com/srs/

These are certainly different from my Bencher RJ-1: http://www.mtechnologies.com/bencher/rj1.jpg

Some of the euro keys, require you to stand up to properly send with them.

73,
Ellen - AF9J

[Mike/W8BAC]

I learned the code using a straight key. I quickly graduated to a iambic paddle and keyer (Heath Kit Memory keyer I built). I tried a bug but never got the hang of it.

In the eighty's I read in QST about G5ZPY and his hand built keys. He got rave reviews and at the time I was traveling back and forth to the UK often. I contacted ZPY and had him build a paddle for me from solid brass. It's a beauty and my favorite.

Mike

[W1UJR]

Cool info Ellen, learn something every day.
Great that someone passes this on, before it is lost forever to history.

RE: Bencher key, did not know they made a black vesion. I have the chrome one and it looks out of place with older gear. The black, aside from the tag, looks like a much older key. I'll have to keep an eye out for one of those.

RE: Euro sending, given the size of those keys, I wonder if the European telegraphers ever developed problems with the "glass arm" which afflicted their US counterparts?
I understand that was one of the reasons for which Horace Martin created the Vibroplex series of bugs.

[AF9J]

Hi Bruce,

Actually, my Bencher RJ-1 is the black one.  I didn't want a chrome key, and it cost less than the chrome plated version.  BTW, it looks like you can still get the black one.  The link to the photo I posted is from the Morse Express website, and they list the black RJ-1 as being available.  Here's the link to Morse Express: 

http://www.mtechnologies.com/keys.htm

My Bencher single lever keyer paddle (I've used a bug so much, that I get screwed when I use double lever paddles), is also black based like my RJ-1.  As for euro operators, and glass arm - yup, I bet they suffered from it big time.  I don't think they sent as fast as US operators.  If I remember right you also belong to SKCC.  If you have the time, go back through the message threads.  I think there was a message thread a few months ago about glass arm, and mention was made about it with regards to euro style sending, and euro keys.

73,
Ellen - AF9J
SKCC # 1369

P.S. - if you want to see what a CW guro knows, read some of the SKCC threads, or talk to David Ring, N1EA.  That guy lives & breathes CW, and was among the last of the Merchant Marine CW operators.  He was involved in one of the last at sea CW SOS emregencies that occurred (back in the 80s).  He's forgotten more about CW & keys than I know.  His wife Cheryl, is also in the Merchant Marine, and is a hotshot CW operator.