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black cat jb-150

552fl

Active Member
Mar 29, 2018
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just bought a little jb-150 the tube in it is a 8417 and does about 90 watts peak..is this about right?will the 6550 tube do a little more?meter on from says set to line ?tuner on back?
 

just bought a little jb-150 the tube in it is a 8417 and does about 90 watts peak..is this about right?will the 6550 tube do a little more?meter on from says set to line ?tuner on back?

I had one of those back in the 70s. Loved it. (y)
But I can't answer your questions. My memory is shot. :(
 
If the amplifier is set up for the 8417 tube that's what you'll need to use.

The input coil has a capacitor feeding into it, and another one feeding out of it. To use a different type tube, those would need to be changed.

The 6550 isn't such a good choice. Never did get the input side to tune properly when I tried it.

73
 
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Thank you very much for letting me know that nomaradio..I was just getting ready to order a 6550 I'm glad I did not I will get the 8417 like you suggest. Could you give me tips on how to turn the little knob in the back to the meter it says set to linewhat does that mean.. thanks very much for your help
 
anyone have one out there?could use as a driver for one of the two sb-220 I have,,or maybe drive the texasstar 500
 
I don't know what the upper limit of the carrier power ("D.K.") is, probably 3 or 4 Watts?

I do know these style of amplifiers don't like a very low dead key (less than 1 watt input) or a radio with wild modulation (see: "clipped" & "swing kit"), these amplifiers produce "swing" on their own; the relay on mine started chattering with too low of a key.
 
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I found the answer on some old threads.. radio 3 Watts dead key.JB 150 at 10 watts or less of dead key let it swing to 100 watts of p e p.
 
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I have about 6 of those amplifiers. I usually set my radio to a 2-3 watt deadkey and set the JB150 to a 3 watt deadkey to get my best results. It all depends on what you are using the small JB amp for. If you are using it alone for local talking then you can run a 10 watt JB deadkey and it works great. But if using it to drive any other amp like I do I set mine at a 3 watt.JB deadkey so I will not burn up any keying transistors in the amp I am driving it into and also to get swing. I drive my Triple Stage Phantom with mine for about 5 years now works great and a great combination.
 
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Thank you very much for the info I appreciate it very much so if I run it into my sb-220 turn it real low like you're saying?
 
LMAO a Heathkit SB220 that amplifier I believe the deadkey will not make much difference it was designed for a 100 watt drive or more so go ahead and do the 10 watt deadkey . I have one of those on the shelf but i like my Phantom better right now for what I am doing. I have seen 200 watts driven into my SB220 regularly before I bought it and no problems. Watch BBI on you tube about Heathkit SB220 amps.Very interesting. I am sorry was not paying attention to what amplifiers you were actually going to run JB150 into my mistake getting ahead of my self.
 
Yes you are right I usually run a Texas Star 350 turn down 200 watts into it but tonight I run the modulator into it and getting like six out of it but everybody said it sounded really loud loud.. so I will keep it at dickey at 10 thank you very much again Roger in Florida...
 
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My JB 150 quite keying up must be relay or something I don't know.. guess I will be taking it to Wolf Radio to have him look at it
 
If it won't key, I would first look at the electrolytic filter capacitor for the relay circuit.

What baffles me now is that nobody has asked how big is the radio you're driving into it.

The JB150 was built to work with a typical tube-type CB base radio of the late 60s. Radios that would bust a gut to show a 3.5 Watt carrier, and 14 Watts PEP.

A fairly-stock 40-channel legal CB radio with only one final transistor is bigger, maybe twice the "swing" of the 23-channel radio from 50 years ago.

And a "10-meter" radio with two final transistors will hit this amplifier at least three times as hard as it's built to allow.

So, what kind of radio are you using to drive it?

73
 

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