My Bendix TA12

[w1vtp]

My Elmer W1GAZ had this as his main xmtr.  He also had a Hammarlund SP-400.  I now have both of his rigs. Looking forward t putting this on the air.

Mike WU2D has a chance at one too.  Mike:  I like your suggestion that we get together on putting our TA12s on the air.

Al

[w1vtp]

More pics. This is a very ham friendly xmtr.  It features 4 separate vfos (roller inductor tuned) an 807 driving two 807s

[W7TFO]

I always thought that Bendix rig was one of the best of WW2.

73DG

[w1vtp]

I always thought that Bendix rig was one of the best of WW2.

73DG

Don - W1GAZ thought so.  He, his friend Vern W1UCC  and Frank W1TAN had one too.  Frank had his built into a neat hideaway cabinet along with a National NC183 Rx.  I like the tube lineup. They all had an indelible influence on me as a JN.

Al

[WU2D]

I remember seeing them for years in the Fair Radio Catalog for 30 bucks plus shipping. Hopefully I can score one and we will get both fired up and put them on the air.

Mike WU2D

[W4AAB]

K4JJV(now SK) in Mobile, AL had one mobile in his Cadillac. He added another 1625 in the final to it. I saw pictures of it, along with his 16 1/2 foot vertical( could only use in the open country). I never saw one other than in the Fair Radio Sales catalog back in the 1970's.

[WB6NVH]

The monkey wrench in the gears for these seems to be that the power supply-modulator is very, very rare (Why? Left in the planes when they were scrapped?) so that you have to make not only a power supply but also a modulator.  Most of us would make a power supply anyway rather than running the dynamotor, but the modulator issue is irritating.

And, you need that external hokey test meter with the cable as for whatever reason, the panel meter doesn't meter everything.  The manuals are also very rare and expensive although I believe someone is reprinting them.

For mine, I was figuring on making a modulator with a pair of 1625's and using an ART-13 modulation transformer.  I haven't done the math regarding a match yet, however.

[w1vtp]

OK on the PS & MOD comments.  Understood.  But that's not a big problem.  Would be nice to have the dynamoter / modulator but a reguular PS going to AC mains will be my approach.  I like the idea of having the TA12 in my Crown VIC as a mobile.  Just need a receiver to go with it and a small AC generator to tow behind.   

My plan is to use a couple of 1625's as modulators with fils wired in series so they can be hooked up to the 24 volt supply that will be needed unless all the fils are rewired.  I'll have to have the modulator configured to have ear splitting, yellowey audio to simulate a military transmitter so I can check into the Military Net Saturday morning and not get kicked off    Interesting that the 12SK7 fils are wired the same way with chan 1 & 2 fils in series and chan 3 & 4 wired in series.  Come to think of it - it might be a good idea to rewire the fils for 12 volts.  That way, I can just hook the TA12 up to the car batt.

I stumbled across an excellent source for the manuals. 

http://www.vmarsmanuals.co.uk/archive/files_index.htm

One is the service manual that includes disassembly instructions.  I don't think the lack of IPA and PA metering is a problem - A regular DC milliamp meter can be put in a box and just plugged into the TA12 during tuneup.  The rest of the time the RF ammeter will tell the story.

Al

[WB6NVH]

I found one of the original meters on eBay for a few Dollars, but of course I could have just made one.  One of the four channels on mine is a low frequency channel so technically I am going to be limited to three, still more than enough.  I am pretty sure I saw an electric channel changing motor in there which had a label saying it was actually a car windshield wiper motor in civilian life.  Mine is in really nice shape and sat all morning at the DeAnza Electronics Flea Market in California at a club estate sale pile, with no takers, until I took it home for $ 5.  So it goes with the modern ham population...

Has anyone got one of these on the air right now?  Can't recall hearing anyone saying so.

[w1vtp]

I found one of the original meters on eBay for a few Dollars, but of course I could have just made one.  One of the four channels on mine is a low frequency channel so technically I am going to be limited to three, still more than enough.  I am pretty sure I saw an electric channel changing motor in there which had a label saying it was actually a car windshield wiper motor in civilian life.  Mine is in really nice shape and sat all morning at the DeAnza Electronics Flea Market in California at a club estate sale pile, with no takers, until I took it home for $ 5.  So it goes with the modern ham population...

Has anyone got one of these on the air right now?  Can't recall hearing anyone saying so.

There is some sort of VLF thing going on at 500 KC.

http://www.500kc.com/

Just looked at the station list and I recognize some AMers

http://www.500kc.com/USA_600_M_Station_ID.htm

This feature might be just the ticket.  I'll have to crack the oscillator cover and take some pics.  Chan 1 was modified in my TA12 to do the first part of 160 meters.  This guy put a lot of work into it.  I don't like what he did with the output hookup.  I may restore that back to the original design.

Al