T47/ART-13 transmitter freq. coverage

[W6MQI]

I just acquired a T47/ART-13 which I hope to get on the air sometime in the near future. I've been doing some reading through the mountain of documentation that I have man those military manual's are wordy. Why did Collins skip the 160m band with this xmtr? Looks like one can squeak down just a bit from 2000Khz but not much.

I'm looking for power supply ideas too hint.. hint..

[KB2WIG]

It was designed as an airbourn transmitter; one with more 'umpf' than the ARC stuff.So, the 'shorter frequencies mean shorter antenas.......... But.... there is an LF mod/add on for the'13... xtal controll.... cant remember what else;


Klc

[KL7OF]

You can pad the out put and get the ART 13 on 160 easily....

[W6MQI]

You can pad the out put and get the ART 13 on 160 easily....

Maybe I misunderstood thought I read some where even padding would only get it down to 1950Khz or so.

[kb3ouk]

It was designed as an airbourn transmitter; one with more 'umpf' than the ARC stuff.So, the 'shorter frequencies mean shorter antenas.......... But.... there is an LF mod/add on for the'13... xtal controll.... cant remember what else;


Klc

I believe the LF/MF oscillator/whatever-it-was only covered something like 300 or 500 kc up to 1500 kc, so there is a gap from 1500 to 2000 kc that it still wouldn't cover. The ART-13 was originally designed for the navy, and 2000 to 18000 kc was pretty much what all of their transmitters were designed to cover. My GO-9, which is claimed to be the largest airborne transmitter the navy had (three sections: MF TX, rectifier, and HF TX, total weight of all three is approx. 120 pounds), covers 3000 to 18000 kc, I wish it did go down to 2000 kc to try and get it down into 160, would be a lot more useful than having the higher frequency coverage.

[KB2WIG]

Now that I'm home, I pulled out my manual and refreshed my memory.
 
From T.O. 12R@-2ART13-2

RADIO TRANSMITTING SET 1N/ART-13
30 MAR 1956.

pp 1-5 (2)b

"  When  the CDA-T unit is utilized, two crystal-controlled frequency bands are provided, one covering the rangge 1670- kc to 18,000 kc. and the other 300 kc to 500 kc.  "

The Bunker 'O dume has this the manual in all 280 pages of glory.
 
http://www.bunkerofdoom.com/lit/art13/TO_12R2-2ART13-2.pdf

 My two '13s are lying under my Tektronix RM45, awaiting my shame to subside and my hope to renew.   I was  able to cross the LV and HV TWO TIMES and let the smoke out.

klc

[AJ1G]

IIRC there was something on how to pad the ART-13 master oscillator down to allow coverage of the full 160 meter band in ER magazine many years back.  It might have been written by  Mike, WU2D, he  might have be using his original call sign WB2UID when the article was written.  Was a simple fix, although a recall something about how  you might lose some grid drive since only the MO stage was padded.

You probably can get down to at least 1985 kc using the set as built.  I used to run mine down there a couple of sun spot cycles ago when poor early morning propagation led us to run, or at least, start the Old Milrad Net on that frequency vs 3885 at 0500 EST.  The GRC-9 will also pull down at least that low as built, I think the WS-19 also could get there.

[K4RT]

The article by WU2D (then WB2UID) is in the December 1991 issue of ER, page 24. Mike wrote that he padded the VFO & 1st multiplier tank using a remotely switched relay.  If you don't have the Dec 1991 issue shoot me an e-mail and I will scan it and send it to you.  It's a one page article that includes a schematic diagram.

Brad

[W6MQI]

If you don't have the Dec 1991 issue shoot me an e-mail and I can scan it and send it to you.  It's a one page article that includes a schematic diagram.

Email  sent.

73, Dave