ART-13 RF Ammeter Scale?

[k6jca]

I recently picked up an ART-13 transmitter, and it's missing its RF Ammeter.  Does anyone know what this Ammeter's scale should be (0 - 3, 0 - 5, or...?)?   I have a couple of spare RF ammeters in my junkbox, and I'm wondering if one of them might be the correct one for the ART-13.

Thanks!

- Jeff, K6JCA

[W7SOE]

I will look at mine when I get home.

Rich

[KE6DF]

Mine is 0 to 5. Presumably amps, but it doesn't say.

It's Western Electric brand if that helps.

[k6jca]

Rats -- I only have 2A and 3A RF Ammeters in the junkbox.

Oh well.  Thanks guys!

- Jeff, K6JCA

[KE6DF]

I have a spare one I could send  you. The problem with it is it has a small chip out of the Bakelite rim. Otherwise it looks OK.

It's in an old ART-13 parts radio.

Not sure if it works, but it's yours for the grand total of $0.00.

Dave

[k6jca]

Thanks very much for your offer, Dave.  It's very generous.  I hope you will allow me to at least pay for the shipping.

My address is:

  Jeff Anderson
  1215 Carmel Terrace
  Los Altos, CA  94024

Best Regards,

- Jeff

[Bill, KD0HG]

I recently picked up an ART-13 transmitter, and it's missing its RF Ammeter.  Does anyone know what this Ammeter's scale should be (0 - 3, 0 - 5, or...?)?   I have a couple of spare RF ammeters in my junkbox, and I'm wondering if one of them might be the correct one for the ART-13.

Thanks!

- Jeff, K6JCA

Bear in mind that there is a shunt across the ammeter in the ART-13.

Mine has a full-scale of 6 amps, but the meter itself is 250 milliamps full scale. It is *not* a 6 amp meter.

Make sure the shunt is there and hasn't been removed.

[k6jca]

Thanks for the information, Bill, I wasn't aware that there might be a shunt resistor.  My ART-13 only has a big hole in the front panel where the meter ought to be and two dangling leads!  No resistor to be found...

[KE6DF]

In the parts radio someone has already unhooked the wires to the meter.

In my complete, untouched ART-13, there is no shunt. Just two wires going to the meter.

In both cases, the meters are Western Electric and have a 0-5 scales.

But you are right, the meters say .25 amp on the face.

The schematic does not show a shunt, but shows the antenna current meter coupled through some kind of link. It's not directly in series with the antenna.

BTW, I used to live in Mountain View for 23 years -- right next to Los Altos.

I send that meter out on Monday. I'll just send it, and you can pay me the shipping when you get it. It can't be much for just little meter.

Dave

[KE6DF]

OK, I looked at it more carefully, and the antenna current meter is indeed link coupled and there is no shunt on my unit. The link/transformer is a round ceramic thing below and to the left of the vacuum relay (looking at the ART-13 from the front). It's about 1 1/2 inches diameter.

If you have that ceramic link piece, and the wires go to the bottom of it, then you are probably set with the meter I'll send you.

If you don't have it, I can't help because the ceramic link is gonzo from my parts radio.

Dave

[Bill, KD0HG]

Senior moment!

Yes, there is an RF transformer to feed the meter, not a resistive shunt.

Sorry about any inconvenience.

[k6jca]

Thanks Dave (and Bill!) for the clarification.  Yes, my ART-13 still has the ceramic thingy.  Although I haven't looked under the chassis yet, on top the only thing that seems to be missing is the meter.

By the way, Dave, I used to live in Mountain View, too.  From the early 80's until 2000 I lived on Bonita Avenue, just a few houses down from Cuesta Park.  (Bonita Avenue intersects El Camino just a few blocks south of Castro -- that corner used to have a Harry's Hofbrau restaurant, and before they put in the Harry's Hofbrau it was a Food Fair supermarket, just in case you are familiar with that part of Mountain View.)

Best regards,

- Jeff

[WA1GFZ]

hi Jeff,
Nice to see you playing with the old stuff.
Jeff sent me some Racal power supply stuff a while back.
I hung out in Mountain View area winter of 1974. had a ball with a high school buddy and his wife. I think it was foot hill college he did a radio program in the afternoon. I was a guest on his program.

[k6jca]

Hey Frank, good to hear from you again.  It's been awhile.  My new call, k6jca, is probably new to you -- I think I was still wa6ahl the last time we talked.

If I recall correctly, you had been hot-rodding a 6830.  How did that go?  I still have a couple here in the rack, along with a few other "high end" receivers.

By the way -- the college was indeed Foothill college (just a few miles away), and the radio station was probably KFJC.

Cheers,

- Jeff

http://k6jca.blogspot.com/

[WA1GFZ]

hi Jeff I think it ran 6 watts but the antenna was way up high.
Steve did this show called West Coast girls. Opened with the Beach boys song.
Still playing with 6830s and have a nice one I did up with a modified DF second mixer module and stuffed 3 filter modules in it using the blue collins mechanical filters. 2 stacked in the A10 slot and a third in the A7 slot between the IF and detector. I'm working on an interface board to go into A3 to grab display data and send it out the remote cable to tune a cubic pre/post  selector.
Also worked with a guy on the West coast to design a A7 module to be a QSD off the 455 kHz to provide I/Q to a computer. This one is in my wideband 6830.
I have 6 different 6830s and a few partial units kicking around. I bought a pile of stuff from Gary W. But his prices got too high. I was building them for around $1100 and selling them for a couple hundred more. The power supply stuff you sent me went into my units to replace switchers.
I've built an HPSDR set up and on the air with Mercury / Penny with other premium recivers hanging off to the side. I compare performance all the time.
Racal beats the QSD all the time under bad conditions but the Mercury is pretty even. I think you were helping Flex guys with the software for a while.
Many of us are playing with softrock and use the flex software. There are some AVC issues on AM but it works fairly well. I'm looking for 6840 second mixers. They added an amp in the LO chain to drive the second mixer at plus 23 dBM.
I think I still owe you around $6 for postage so if you ever need any parts I would be glad to help if I can. 

[k6jca]

Hey, don't worry about the postage, Frank!

By the way -- if you'd like to see some of my Racals, go to my blog at:

http://k6jca.blogspot.com/

There are some shack pix there.

73,

- Jeff

[WA1GFZ]

Nice stuff!

[W2JBL]

the stock RF ammeter in my ART-13 died years ago. i removed the coupling link setup it had and tossed in a 5 Amp GE meter i had in series with the lead going to the SO-239 i mounted on the side. works nice and reads about 2-2.5 amps into 50 ohms. this is with 1650 volts on the plates of the 813 and 811's. modifed heising around the mod transformer is a good idea if you run the rig at those power levels.

[WU2D]

Right! Your 3 Amp meter would be fine.

Mike WU2D