The Collins ART-13

Discussion in 'Amplitude Modulation' started by N6YW, Jul 26, 2016.

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  1. KC9UDX

    KC9UDX Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    You should see how they do it in TVs. I always thought they should use a TV filament schematic for those series/parallel resistor problems in school.
     
    AF6LJ likes this.
  2. KJ4YEV

    KJ4YEV Premium Subscriber QRZ Page

    Agreed. If it were not for TV, we would not have all those oddball tubes with 36V, 18V, 17V etc. Heaters.
     
    KC9UDX likes this.
  3. KC9UDX

    KC9UDX Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    It's good to keep in mind that these exist.

    A set of 17JB6s as Drake spares are dirt cheap. When the day comes, a 17V power supply is easy to improvise.
     
    KC8YLT, KJ4YEV and KD2ACO like this.
  4. N6YW

    N6YW Ham Member Volunteer Moderator QRZ Page

    The ART-13 has a lot going for it in terms of servicing in the field.
    It was designed for easy replacement of tubes, relays, clock mechanisms and removable oscillator and audio
    chassis units, held with captive screws. Not exactly the easiest to repair when having to get in deep but once
    you do, it becomes clear that the genius of it's design was also mixed with some compromise due to the
    technology and manufacturing practices of the era. The wiring looms are a pain in the ass to distinguish
    due to coding of the cloth sheath which is often faded. If you stick with it, you'll find the error and make
    the repair and move on.
    One of two that I first owned had factory errors that likely resulted in the repair depot not being able to
    figure out the problems it had. Hence, it most likely sat around for decades on a pallet until sold off.
    It became the donor to the other radio which is pictured earlier on this thread, which actually worked.

    Two items should be addressed when using the ART-13 for amateur radio. The use of additional C at the
    antenna output is needed for maximum efficiency in loading the tank circuit for 160 & 80-75 meters.
    Some use fixed value doorknob types or air variables. Both will work. I use a 500pf air variable and it works
    fine. These radios were designed for aircraft use, so a trailing wire or fixed long wire was used, so the tuning
    requirements were different than using a dipole like many of us do.
    The second item is the use of a fan on the back of the radio behind the 811's and 813. These do emit a good
    deal of heat and it's more intended to make the operating environment comfortable than anything else.
    It won't hurt the radio to run it without one as it wasn't designed with one to begin with but just the same
    it's a good idea to use a fan, at least to draw the heat away from the chassis. When running plate voltages
    upwards of 2000 volts, which mine does, it's a very good idea because the tubes run much hotter.

    I have read some various details regarding audio modifications for the ART-13. Some are basic and do the
    job nicely while others are quite invasive. While the modulation iron is quite good for it's size we have to
    remember that this was built for the war effort, not broadcasting yet some ops feel the need to max out
    the audio in order to keep up so to speak. I don't follow that trend at all and I am not a purist either, but
    rather a realist. Old parts wear out, so while you're in there replace the coupling caps and bypass caps
    in the audio amp. Pretty simple to do and adding a little more C to the audio path helps to a point.
    I used .047 throughout and it turned out fine, sounds great. There are still limitations connected with
    the mod iron and other design factors, but it will still sound really good on the air. The use of the venerable
    D-104 is a good choice but I use a little bit of audio driving before the mic input just to give it a boost
    and I prefer a dynamic mic, like a Shure SM-57. This audio driver can be anything that can provide that
    little bit of "nudge". I use a W2IHY EQ preamp that was given to me. Surprisingly it works pretty damn well
    so why not? But, I do plan to try one of the K7DYY preamps designed for installing into a D-104.
    They sound really good too. Whatever works, right?
     
  5. AL7RU

    AL7RU Ham Member QRZ Page

    I've come close to buying one from time to time. I've been in AM nets with guys that run them and they do sound pretty good. Once I got my Gates I kinda lost interest but the Gates is gone. Still, if I could find a Globe King or a Viking 500 under somebodies bed I could learn to be pretty happy too. I think one purest I talked to one day had rebuilt the dynamometer that was designed for it so that it ran on 60 cycle power. Memory problems here.....maybe he built a 400 cycle power supply for the dynamometer. I disremember.

    Dan
    AL7RU
     
  6. W5BIB

    W5BIB Premium Subscriber QRZ Page

    The clickety-clack of the relay when on CW will drive a normal house-hold crazy !!!:eek: (I really think it's why my folks signed for me to join the Navy @ 17 years old !!)
    A center-tapped pole-pig gave me 1200v with a pair of 866A's. I loved that old rig back in 1963. :) (I even used the original PTT carbon-mic. ya had to beat it on the desk every so often !!)
     
    W2VW and N6YW like this.
  7. KM1H

    KM1H Ham Member QRZ Page

    The ART-13 was proudly preceded by the USN ATC and became the ART-13 when the USAAF decided to replace their drifty and mechanically unstable BC-191 and 375's in late 43, early 44 and the new JAN designation took over.

    My own is an ATC that just makes it to 17M without mods. OTOH the audio section is "improved" and the HV is a sane 1100V.


    Dont overlook a Hallicrafters HT-9 especially if it has the various coils. An easy 100-120W of AM without the ARRL mandated bandwidth restrictions.
    There were two versions, a prewar black version and a gray one in 45-46.

    A HT-18 makes a nice VFO as do several other choices.

    Carl
     
    Last edited: Aug 13, 2016
    N6YW likes this.
  8. K5UJ

    K5UJ Ham Member QRZ Page

    WRL also had a rig around 1950 I think, that ran a single 812A modulated by four 6L6s. I'm pretty sure that's right. the WRL-175 if I'm not mistaken. One rig I have never seen anywhere is the original HT.
     
  9. K4KYV

    K4KYV Subscriber QRZ Page

    I used the carcass of one of those rigs to build the RF exciter that ran my single 304TL back in the mid 60s. After moving into the present shack, I resurrected it to drive my 8005 rig while the HF-300 transmitter was being disassembled, moved from the upstairs room in the house, and re-assembled in the shack. I still have a copy of the original schematic, plus the schematic of the exciter I built out of it. It still runs a single 812 (the original tube it came out with) or 812A.

    I changed the first-stage locktal equivalent of a 6V6 over to a 6AG7, the 2E26 to an 807, and changed the link coupling between driver and final to a single capacitively coupled tuned circuit, getting rid of one tuned circuit to adjust, plus enough other modifications that it barely resembles the original transmitter. I replaced the original panel with a new black wrinkle one, and installed two separate Weston meters, one to monitor final plate current and the other to serve as the multi-meter to monitor the other stages. I never got the 6L6 modulator that went with it. I once tried to sell it, but no takers, so when I made the move I was glad I still had it.
     
  10. N6YW

    N6YW Ham Member Volunteer Moderator QRZ Page

    Please share it with us by starting a new thread about it!
    Post photos and some additional background.
     

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