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THE AM BULLETIN BOARD => Military Amateur Radio Section => Topic started by: w1vtp on April 01, 2018, 12:31:38 PM



Title: My Bendix TA-12 with dyno / modulator
Post by: w1vtp on April 01, 2018, 12:31:38 PM
This is my Bendix TA-12. My mentor Don, W1GAZ promoted this transmitter along with the Hammarlund SP-400, an excellent pair. My transmitter continues to be in a state of stasis because I don't know how to safely get rid of the green corrosion that is on the rotary inductors.  The MP28a dyno / modulator seems to be in new unused condition (dunno why the tape was put over the vent holes on the dyno)

I'll upload several pics in successive posts

Al


Title: Re: My Bendix TA-12 with dyno / modulator
Post by: w1vtp on April 01, 2018, 12:34:38 PM
Pic set 2


Title: Re: My Bendix TA-12 with dyno / modulator
Post by: w1vtp on April 01, 2018, 03:15:31 PM
set 3


Title: Re: My Bendix TA-12 with dyno / modulator
Post by: w1vtp on April 01, 2018, 03:19:41 PM
Set 4


Title: Re: My Bendix TA-12 with dyno / modulator
Post by: PA0NVD on April 01, 2018, 03:38:48 PM
That's a nice set, please tell something about it. Are the tubes 807? The pics are a bit too large to download, every pic takes about 6 minutes!!
Interesting the combination of mod and pwr supply!


Title: Re: My Bendix TA-12 with dyno / modulator
Post by: Opcom on April 01, 2018, 07:55:59 PM
Very beautiful set!


Title: Re: My Bendix TA-12 with dyno / modulator
Post by: AJ1G on April 01, 2018, 09:31:18 PM
Re the tarnish on the roller inductors, did you try Brasso or silver polish? You are lucky to have the dyno/modulator as well as the transmitter.  Many transmitters but few dyno/mods out there...


Title: Re: My Bendix TA-12 with dyno / modulator
Post by: PA0NVD on April 02, 2018, 06:50:14 PM
Hi Al
I had once a roller inductor that had the same problem. It was mainly a kind of grease they used that had turned bad, that may have been a little acid or so and provoked the problem. I used a rough type of cloth with alcohol to remove the green / blue grease.


Title: Re: My Bendix TA-12 with dyno / modulator
Post by: w1vtp on April 02, 2018, 07:10:34 PM
That's a nice set, please tell something about it. Are the tubes 807? The pics are a bit too large to download, every pic takes about 6 minutes!!
Interesting the combination of mod and pwr supply!

PA0NVD:

I assume you mean the file size not the picture dimensions. The transmitter has oscillator / buffers of 12SK7's  The output consists of 2 x 807s in parallel. The 807s are driven by a single 807.  In my opinion a perfect tube linup.  The modulator consists of push pull 807s driven by a 6N7 / 6F6 driver.  The whole transmitter was a well designed unit used by the Liberator bomber and other WW2 aircraft.  

PA0VD, I'll customize some highly compressed images that are without loss of detail and picture size.  I've contacted you via your QRZ email to determine your comfortable file size per email.



Title: Re: My Bendix TA-12 with dyno / modulator
Post by: Tom W2ILA on April 03, 2018, 08:15:32 PM
Great looking set!  And a nice S38 also.
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