AN/ART-13 on the air

[iw5ci]

After a struggle research i finally god a nice AN/ART13 trasmitter (here in europe it's more common the French labelled version).

You can see the photos and a little video about autotuning in my blog:

http://boatanchors.tumblr.com/

I have a couple of questions:

a) I have ordered 3 knob spare from fairradio, there is something i must know before removing the original ones (3 are chipped) or just unscrew from the little holes of the nuts?

B) why the coarse antenna tuning (second from left) is so stiff to rotate even in manual mode if locked? if i ever use the radio in manual mode, can i leave it unlocked?

C) i know i must add a capacitor to use the trasmitter in 80 and 40 meters. Which kind of capacitors do you suggest (i heard about 300pf for 80 meters and 1500-2000 pf for 40 meters) ?

73'

[Bill, KD0HG]

Yes, you can leave the coarse antenna tuning not locked, but then you can't use the autotune feature. You can try to lubricate the mechanism behind the front panel.

The ART-13 was designed to be operated by an airman wearing flight gear and thick gloves, so the knobs are stiff.

Yes, use 300-500 pf loading cap on 80 and and use the same on 40 to start. 100 pf on 20 meters. Or you can connect a 2x or 3x 365 pf air variable capacitor to the terminal to experiment with.

[Todd, KA1KAQ]

The ART-13 was designed to be operated by an airman wearing flight gear and thick gloves, so the knobs are stiff.

Most of these were set up on the ground before a mission, requiring no tuning in flight (though it could be done if required). The autotune feature was a big leap forward for in-flight frequency agility, and one would guess that Collins put the emphasis on that aspect and less on the manual/set up side.

That said, many a ham has come across gummed up or burned out auto tune motors and used nothing but the manual approach to operate the rigs. Cleaning and re-lubing is always a good place to start.

[KB2WIG]

Don't drop the knobs. They break very easily.


klc

[Bill, KD0HG]

The ART-13 was designed to be operated by an airman wearing flight gear and thick gloves, so the knobs are stiff.

Most of these were set up on the ground before a mission, requiring no tuning in flight (though it could be done if required). The autotune feature was a big leap forward for in-flight frequency agility, and one would guess that Collins put the emphasis on that aspect and less on the manual/set up side.

That said, many a ham has come across gummed up or burned out auto tune motors and used nothing but the manual approach to operate the rigs. Cleaning and re-lubing is always a good place to start.

Good info, Todd.
Thanks.

[iw5ci]

I see... 3 of 6 of my knobs are dented
just ordedered 3 spares from Fair Radio.

i managed to tune the radio on 80 and 30 meters without condensers, i have about 100W carrier on 80 and 70W on 40 my external power supply gives just 900V of anodic is it normal? Probably without the condenser i cannot gain the correct load of the PA and the power is less than what i can get with the condensers..

[KB2WIG]

Gud luck in getting her running.

From  T.O. 12R2-2ART13-2   Handbook and Maintenance Handbook.


Section 6
 CW output on 4Mc. 80.0 watts;7.0Mc.  90 watts; 18.1Mc  65 watts

A few voltages,

813 plate, 1150V   Screen, 420V    Grid, -40V    
811 plate, 1150V
1625 plates; v102, 430V, v103, 420
837 plate, 410 V




go here for a free, online  manual

http://bama.edebris.com/manuals/military/an-art13/


klc

[Todd, KA1KAQ]

Bill, we're not only fortunate that we get to enjoy this cool old stuff, we're VERY fortunate that we don't have to operate it where and how our fathers and grandfathers did. Someone once muttered about the flaking black paint on an ARC-5 set and wondered why they didn't do a better prep job. The answer from an old timer was "We didn't have a long life expectancy for them". It might make 25 missions or get shot down on the first one.

If you decide to set it up for auto tune service, just be sure to clean and lubricate the mechanism as Bill mentioned, or you'll burn up the motor.

Considering the technology is from a pre-war design, it's pretty amazing stuff. Even today there's nothing quite like watching the knobs spin and whirrrr as it re-tunes.

[w3jn]

Bill, we're not only fortunate that we get to enjoy this cool old stuff, we're VERY fortunate that we don't have to operate it where and how our fathers and grandfathers did.

And how.  I couldn't imagine being a scared 18 year old kid radioman-gunner on a B-25, trying to get out a mayday on a POS BC-375 after a japanese AA shell hit the port engine...

We owe each and every one of those old buzzards that are left a huge debt. 

[W7SOE]

I do 150W with 1200V on the plate (loaded) so your 100W at 900V seems reasonable.

Rich