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Author Topic: Is this a Johnson KW Matchbox?  (Read 5651 times)
W0OPW
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« on: October 25, 2011, 10:48:25 AM »

I picked this up at a yard sale recently for $15. There are no markings of any kind  but the components are huge. The relay is not hooked up. Anyone have photos of the internals of a KW Matchbox to compare with?

<IMG SRC="http://pic100.picturetrail.com/VOL702/13362964/23797014/399127955.jpg" border="0" alt="Image Hosting by PictureTrail.com">

<IMG SRC="http://pic100.picturetrail.com/VOL702/13362964/23797014/399127954.jpg" border="0" alt="Image Hosting by PictureTrail.com">
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G3RZP
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« Reply #1 on: October 25, 2011, 01:48:38 PM »

I don't know if it's the 1 kW version but even if it's the 275 watt one, I suspect you could get $50 with no problem!
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W8JI
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« Reply #2 on: October 25, 2011, 01:55:16 PM »

No.

It is the 275 watt unit.

The kW unit has an edge wound inductor and much larger components.
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G3RZP
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« Reply #3 on: October 25, 2011, 02:00:46 PM »

Tom,

Is it not worth $50 of anyones' money, though?
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N2EY
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« Reply #4 on: October 26, 2011, 02:51:48 AM »

It's the components of a 275 watt Matchbox repackaged. Why, I don't know.

btw, IIRC the Matchbox ratings are DC input ratings on *AM*, not PEP.
275 watts input equals about 180 watts carrier and over 700 watts PEP.

73 de Jim, N2EY

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W8JI
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« Reply #5 on: October 26, 2011, 03:01:10 AM »

Tom,

Is it not worth $50 of anyones' money, though?

It would be worth about $100 or so in the right box with the right wiring. :-)

I'm not sure what it is worth as it is....I guess what someone will pay.

I've owned them. It is not a big tuner. Remember the power rating was DC plate input back then. That tuner was rated at 275 watts PA PLATE input on AM, or about 500 watts of RF PEP output maximum. Something like a Viking Valiant was the matching rig, so about a 150 watt output CW rig is a good match.

It is suitable for barefoot operation with 150 watt -200 watt radios.
« Last Edit: October 26, 2011, 03:02:52 AM by W8JI » Logged
N3QE
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Posts: 5585




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« Reply #6 on: October 31, 2011, 06:34:52 AM »

I picked this up at a yard sale recently for $15. There are no markings of any kind  but the components are huge. The relay is not hooked up. Anyone have photos of the internals of a KW Matchbox to compare with?

<IMG SRC="http://pic100.picturetrail.com/VOL702/13362964/23797014/399127955.jpg" border="0" alt="Image Hosting by PictureTrail.com">

<IMG SRC="http://pic100.picturetrail.com/VOL702/13362964/23797014/399127954.jpg" border="0" alt="Image Hosting by PictureTrail.com">

Looks to me like some sort combination of parts using the 275W matchbox components (inductor and physically smaller variable capacitor and I'm assuming the switching arrangement) but with a much (physically larger) bigger output capacitor (the one with the wide plate spacing.)

The insides of the cabinet doesn't look like either a 275W or KW matchbox. None of the big passthru insulators.

The fly-wires to the inductor... don't look like the original Johnson wiring. I assume they go down to switch below it.

Tim.
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KA5N
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« Reply #7 on: November 07, 2011, 07:46:42 AM »

    You have to have a vivid imagination to see a Johnson Matchbox in this kludge.

The original coils had two different winding pitches .  The end windings were alike but the
center section was a different pitch.   

It appears to be a sort of copy of a Matchbox with similar components.

You would be lucky to get $10 for it unless someone just had to have the variable cap.

Allen
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K9SQG
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« Reply #8 on: February 22, 2012, 08:51:16 PM »

Well, yes and no. The coil and small variable capacitor look to be from a 275 watt Matchbox and the large variable capacitor looks to be from a 1 KW Matchbox.  Relay and most of the other components are from neither Matchbox.

73,

Evan, K9SQG
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