[Milsurplus] Bendix TA-12
Michael Hanz
aaf-radio-1 at aafradio.org
Fri Aug 16 16:18:26 EDT 2019
Just to add to Mike's excellent tabulation, here is the TA-12D coverage (from the Bendix equipment manual for the Commonwealth version of the Douglas A-20 Havoc called the_Boston_.)
Ch. 1 - 1200 to 1540 kHz
Ch. 2 - 2000 to 3400 kHz
Ch, 3 - 3000 to 4800 kHz
Ch. 4 - 4370 to 7000 kHz
- Mike KC4TOS
On 8/16/2019 3:03 PM, Mike Morrow wrote:
>> Can anyone tell me the frequency coverage of the Bendix TA-12G
>> transmitter? I’m trying to make some equipment ID cards for a
>> radio display and can’t find my TA-12 manual. Note this is for
>> the G model, not the more common B or C.
> It's not likely that your TA-12 manual would have helped. The TA-12G is the last and most refined of the TA-12 series, with some improvements in the PA output tuning capacitor configurations and a small "wave meter" neon indicator to help assure correct MF channel 1 tuning. The TA-12G is built by Northern Electric Company, and it should have come with a heavy paper calibration graph stowed under the transmitter case.
>
> The first three TA-12G channels have the same frequency range as the TA-12B. The fourth channel is as shown below.
>
> Ch. 1 - 300 to 600 kHz TA-12B TA-12C TA-12G
> Ch. 2 - 3000 to 4800 kHz TA-12B TA-12C TA-12G
> Ch, 3 - 4000 to 6400 kHz TA-12B TA-12G
> 4800 to 7680 kHz TA-12C
> Ch. 4 - 4370 to 7000 kHz TA-12B
> 5750 to 9000 kHz TA-12G
> 7680 to 12000 kHz TA-12C
>
> Frequency coverage overlap of the three remotely-selected HF channels allows more flexibility for using channel frequencies relatively close to each other. The TA-12B has the best channel overlap but coverage stops at 7000 kHz, The TA-12G has less channel overlap but coverage stops at 9000 kHz. The TA-12C has NO channel overlap, but coverage stops at 12000 kHz. Unfortunately, that was not especially useful in the WWII era, nor was it supported by the associated RA-10-series receiver whose coverage ends at 10000 kHz.
>
> The RA-10DB receiver's coverage is;
>
> Band 1 - 150 to 400 kHz
> Band 2 - 400 to 1100 kHz
> Band 3 - 2000 to 5000 kHz
> Band 4 - 5000 to 10000 kHz
>
> I have always admired this particular Bendix system. I have:
>
> RA-10DB LF/MF/HF manually-tuned receiver with dynamotor and
> with MR-11D loop relay unit
> MR-9B Receiver control box
> MN-20E DF Loop
> MN-52B DF Loop control box
>
> TA-12B MF/HF four-channel transmitter
> MT-53B MF tank coil
> MT-51C Transmittee control box
> MP-28BA Modulator/dynamotor
>
> Plus other ancillary items.
>
> It seems a pretty good compact 1940-era system that provided a four-channel HF communications set with some LF/MF DF capability.
>
> Mike / KK5F
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to aaf-radio-1 at aafradio.org
--
Michael Hanz - KC4TOS
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20190816/6e0d5b40/attachment.html>
More information about the Milsurplus
mailing list