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    HG 2879 die/ flange

    i figured I’d post this for informational purposes. The die or flange on these new DEI, HG and RFP 2879’s is larger than the old Toshiba flange. If you have to replace Toshiba with newer version, you will have to pull board and use a dremel to make transistor opening larger. I’ve had a lot...
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    ECA 1102 filament transformer

    anyone ever use one of these. These were used in the Henry 8k amplifiers. I picked up a couple a few years ago and just got around to using one. The ones I have seem to run high on voltage. My line voltage is 249vac so I put on 250V tap. I was getting 8.5vac at tube. Each leg on contactor...
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    Toshiba 2SC2290B

    Does anyone remember what the date code was when they started making the 2290B? It’s been so many years ago that I do not remember.
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    Henry 3kD Premier ( 3cx1200D7 model)

    Anyone know what the proper glitch resistor is for this unit? It's the desktop model. Glitch is blown, had bypass capacitor at Millen connector short. I think it's a 10ohm at 20w but not positive. Anyone know?
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    Clamp for LDMOS

    looking for clamp/ holder for blf188 device. Anyone know where to get these?
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    Line sampler for spectrum analyzer

    Im looking at getting a spectrum analyzer. I know most will only take 100v max for input voltage. What I was wondering is what would be a good sampler to use that would attenuate / have enough db attenuation to drop voltage enough for say legal limit. Maybe a bit more. I want to experiment with...
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    Tuned input for Tetrode

    I'm thinking of building a HF amp using something with either a Russian 4cx400 or 4cx800 equivalent. But I'm not sure on the best way to do a tuned input. Any suggestions or good links I should read up on?
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    E.F. Johnson capacitor chart

    Anyone know where I can find link or chart that has the different values and ratings? I have a ton of stuff here but was wondering what the actual V ratings of some of this stuff was.
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    IBM 21L2906

    It's a 48v @ 73a switching supply. I wondered if anyone has had or used one of these for a 50v supply. Mine didn't come with any labels or pin outs. So I haven't figured out how to hook it up yet. Anyone have any ideas or advice or even a link somewhere. I spent an hour on Google, there are a...
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    Maverick 250

    Friend brought over a Maverick 250. Looks like it was converted to 10/11 meters. My problem is, the Tune cap is arcing. Is this a common problem? I was using a 148glt to test with. It does 12w pep. I'm just not sure how to decide it its a cap failure or if its parasitics going on. The arc that...
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    2057's

    What is a single tube rated for roughly. Someone brought over an amp that has 3 driving 8. I got it up and running. Not sure what the problem was really it works on low and hi. Low does about 500 pep. Hi does around 1400 top end. I'm sure that's more than what those tubes are rated for for...
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    Heathkit SB220

    Have a heathkit here, everything looks right, have to hook up my external V meter and see if plate V meter is correct. Looks kind of low. May just be meter. Anyways I was just using a barefoot 148 to test amp. With maybe 15w pep in, I am getting close to 200pep out. But what I don't like is the...
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    black Cat JB2000

    So a friend brings over his neighbors amp over. Recently 1 of the tubes blew and he replaced only the one. I have replaced all the diodes on doubler circuit. Has a new cap bank. Replaced the resistor for metering, B- floats. Installed a 50k resistor for bias shutoff. It only goes to ground when...
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    Pride KW-one

    Friend of mine dropped off a pride for me to look at. Said that when amp is keyed, you can hear arcing. I haven't hooked it up yet, but I took the cover off to investigate. The band switch is heavily pitted. The tank coil used for 10 meters is pretty much black on 4 of the turns where it is...
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    Voltage drop

    A friend is bringing over a sb220 amp. The problem with it is that when amp is keyed, the plate volts drop to almost zero. I am thinking the cap bank probably needs replaced. Anyone ever see this happen in an amp before?
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    3cx....A3 or A1 tubes

    I was wondering, I see so many of the F1/F3 or the A1/A3 tubes on ebay cheap and a lot are NOS. What is the difference. I know they are lower gain. Maybe grid driven? Somewhere I saw or read that the grid had to be isolated from ground? Just wondering if anyone had insight on this or could...
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    Dentron MLA-2500B

    Just had a friend bring over this amp. The amp needs new capacitors. I have never seen a capacitor with 4 pins. 3 are used on each of the caps. I was thinking of replacing with 8 x 220uf@450V. Just wondering if anyone has installed their own cap bank instead of say using the Harbach Kit. I know...
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    kvar

    I was wondering if anyone knew or could point me in the right direction. I have been looking at a lot of the russian surplus stock of capacitors. Usually they do not have a current rating. Just a voltage rating. Some will say 6 or even 90kvar. Is there any way to tell what the capacitor will...
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    4cx250B

    I just gutted and redid a single 4cx250b amp. I have 1200vdc on plate ( old amp had 2400Vdc for a single 250B) 300vDC on screen and about -55v for bias. I am getting about 300-325W pep for a single 250b. I noticed that as soon as plate/screen switch is turned on, tube starts to heat up. I have...
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    6v transformer

    Anyone know where to get a 6V transformer @3 amps. Looking for one for a filament for a 4cx250B. RF parts from what I saw strictly has 6.3V.