The AM Forum

This is what followed me home this afternoon.  A Mackay HF transmitter Type 2003 and the receiver is a type 138-B
2-24 MHz 250 watts cw.  Anyone know anything about this jewel or where I might find a schematic?  I have a modulator that will work great already.
I also have the VLF transmitter and receiver that goes with this but that is another story.  The final tubes are a pair of 813's.

Drooling... :P'

73DG

PANT!  PANT!!

Pics of the inside?

If it proves rare, these tactics may help:

• Search for maritime radio and marine radio historical sites.
• Send comments to maritime museum curators stating your intention to restore it and ask if they know of resources.
• Find associations of old maritime radiomen. If they have a newsletter they might mention your need and a member respond.
• Maybe the coast guard radiomen associations might have someone that collected various manuals. Those were "real" radio operators, so..
• Find a Mackay or maritime electronics museum online.
• search 'google images' for your model numbers and find the pages they are on, then inquire.

Those techniques are how, after 2 years of searching, I found the manual to a Radiomarine Corporation of America URT-12. It was in an old box of papers up on an elderly CG radio operator's garage shelf and had not been touched in 20 years..

Unless a manual vendor just happens to have them, most of the books were pitched when the radio gear was replaced, often happening only when it was thoroughly used up as is everything on a vessel.
The gear was not as favored by hams as one might think and was often not desired due rust and corrosion.
Be prepared to search for a long time, and to rejoice when you do find it.

some leads for searching:

http://www.radioblvd.com/nevradiohist.htm (http://www.radioblvd.com/nevradiohist.htm)
http://www.radiomarine.org/ (http://www.radiomarine.org/)
http://mmncny.org/collections/radio-direction-finder/ (http://mmncny.org/collections/radio-direction-finder/)
http://www.comm-one.org/index.shtml (http://www.comm-one.org/index.shtml)
https://www.google.com/search?q=mackay+radio&biw=1521&bih=915&source=lnms&tbm=isch&sa=X&ei=XODOVPjKIsWqggSBiIDQBQ&ved=0CAYQ_AUoAQ (https://www.google.com/search?q=mackay+radio&biw=1521&bih=915&source=lnms&tbm=isch&sa=X&ei=XODOVPjKIsWqggSBiIDQBQ&ved=0CAYQ_AUoAQ)

By all means if you find it, please scan at high resolution and post it! (I am a bit selfish in  that request and like this kind of gear, love to read the manuals and diagrams)   ;D
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I've got the LF transmitter mates to those, the Mackay 2010 and 2012B along with the emergency LF regen the Mackay 3002C. 813 finals.

The receiver goes up to about 1 mc. and only runs B+ at 90 volts, so I'll probably get that running but what to do with a +/- 500 kc transmitter.

It's hard to find info on these although I did find the schematic for the 9001 receiver.

My bits came of the old NASA Range Sentinel tracking ship.

"The receiver goes up to about 1 mc. and only runs B+ at 90 volts, so I'll probably get that running but what to do with a +/- 500 kc transmitter."

A 600 Meter Ham band rig?

http://en.wikipedia.org/wiki/600-meter_amateur_radio_band (http://en.wikipedia.org/wiki/600-meter_amateur_radio_band)

The 600 meter (or 630 meter) amateur radio band is the newest frequency band allocated by the International Telecommunication Union (ITU) to amateur radio operators, and it ranges from 472 to 479 kHz.

Back in the dinosaur age of the 1970s while working for a bunch of maniacs who had a high-class marine radio company in Mamaroneck NY, I had the privilege of decommissioning a boat load (ha ha) of these and RCA radios from More Mac container ships.

I did inquire about obtaining some, but they claimed that they were being stored in a warehouse, somewhere. :(

So, somewhere in Brooklyn (likely) there was a warehouse with maybe hundreds of RCA and Mackay rigs... they were replaced with all-in-one 1kW synthesized vfo, auto tune SSB rigs... about 1/10 the size.

I use the predecessor to your transmitter - Mackay 167BY from WWII. The tube lineup is 76-6L6-(2x)813.
After yours was the 2013 using 12AT7-6146-(2x)813 that ran A1 and A2 CW.
The WWII rig used a goofy trickle-down voltage where 1200V was the only high voltage.  If you want to plate modulate that rig it needs eliminating the trickle-down scheme and providing 400V for the 76 and 6L6.  It's easy to do.
The 2013 from the '60s until the '90s was more traditional with a separate 400 and HV supply. A separate plate speech amp was available to drive the CW A2 modulator. 

I have documentation for the 167BY and the 2013.  Let me know if either might be useful for you.
Is that a Collins 300g to the left?

Tom

Bear,
         Mamaroneck NY. Any association with TMC?

Phil

"High class" - me thinks it was Radcom.

Correction...The Mackay regen is the 3002C, schematic and parts list attached.

These guys have a Mackay setup in their museum and have at least some Mackay documentation...

http://www.chathammarconi.org/Exhibits.html

I brought these two transmitters out and cleaned them up some.

They are the actual two transmitters on the right in the panel above.

The 2012 tube lineup was 6AU6, 6146, and 2x 813 PA. A2 depended on the
modulator resident in the ac power supply. Output is listed as 250 watts.


The 2010 tube lineup was 12AU6, 12AQ5, 2x 6146 PA and 2x 6146 A2 modulator. It ran on 12V battery and mg set. Output is listed as 40 watts.

I'd originally offered them to a museum and just renewed that offer but if they don't want them I'll list them here.

I figured I'd just renew this thread since the pictures and other info are here.

I still can't find a schematic but It's be pretty easy to trace the circuits.

Greg

I've also got the power panel around here somewhere that'll go with them. No tubes in them except for the oscillators. They've both got a full set of xtals.

Several years ago, picked up a RCA receiver that from what I was told was part of a Radiotelephone system built for the USCG in the late thirties or early forties. Was never used and I got tons of receivers anyway but have to say that the build quality and just the general appearance of the radio is such that I keep it around. It only covers 1.5 to 4.5 MHz in one band but works well on 3885 for copying AM.
In this picture its paired with a 12-volt solid state power supply for use in the field for doing a vintage field day operation. Think just looking at the quality of this radio have to say at that time RCA may have produced the highest quality Marine radios, too bad just about any of that stuff that was built was beat to death by the time it was taken out of service or otherwise just scraped being no one wanted any of that old HF AM stuff back in the seventies when it all went away.
Have no idea how something like this RCA receiver survived for all this time without being used or modified by some Ham years ago.

Where did you get it?  The picture you supplied looks like it was taken on board ship, judging by the way the overhead looks.  From a ship breaker?

Great find, sounds like Tom W2ILA has the info you need. I once saw a similar Mackay transmitter, maybe the same one as yours, removed from the Mackay radio suite racks in the soon to be ex-radio room and awaiting disposal from a ship that had just converted over to  a GMDSS system on the bridge.  It seemed the construction quality and the sheet metal work of it was a lot like that of a Heathkit DX-100 or an Apache. It was probably new in the early 70s. 

The whole thing was intact on the NASA Range Sentinel tracking ship when the picture was taken except for the SW receiver. It was removed for a museum ship and then bits and pieces disappeared over time when the museum didn't do anything with it, until this was all that was left. I rescued it back about 8 years ago. It's a shame because the ship that it was supposed to go into had the same rig when it was in service. The radio room is completely empty now. "Professional" museum management is not a replacement for people who can relate to and love those ships. They managed to drive away most of a very dedicated volunteer group.

It's got a build date of Aug 1963.