The high-temp red silicone rubber is available from Alpha Power (previously ETO). Inexpensively by the sheet. Scissors and glue, and you're all set. -WB2WIK/6 "Success is the ability to go from failu
CCI (Communications Concepts) sells LP filter kits to go with their Motorola App-note based amplifiers, for users to homebrew a bandswitching filter bank and be compliant with FCC spectral purity req
The Mot App Note (and Engineering Bulletin) amps sold for linear service do have active bias circuitry. I've built several of these, and took some data on the EB-63 model a few months ago. Using a CW
Wow, Steve. You're fortunate. I've been a ham almost 38 years (although this is pretty irrelevant, since most of the "problems" have surfaced in the last 5-10 years), and I've had *lots* of problems
[Steve Katz] I guess I have to ask: Biased by what circuitry? A diode? (I'd really like to know, since I don't have anything made by Palomar...) -WB2WIK/6
You can't use an Ohmmeter to test high voltage rectifiers. You can use a Megger or Hipot tester, which provides substantial high voltage applied to the rectifier to monitor the breakdown voltage (app
Hi Jeffrey, I cannot imagine why you'd need a high voltage capacitor in the "loading" position of an output network for a 100W amplifier. Presumably, in that position, the capacitor is across a 50 Oh
My SB-220 used to run over 5kWp output in pulse service when I tried it for radar... -WB2WIK/6 "Success is the ability to go from failure to failure with no loss of enthusiasm." -Winston Churchill To
[Steve Katz] I surely have no data, but I do have an AL80B on hand and it doesn't require anything close to 100W to drive to Ip >400mA. In fact, my exciter in its TUNE position, which runs half powe
Hi Rich, It depends on the band and the load, but usually ~50-65W for 550mA Ip. At that load point, Ep is ~2650V or so, and Po ~950W. Anode gets orange after about 30 sec key-down, but tuning to that
K9VUJ, the relay in the AL-80 pulls in in much less than a second and barely makes a sound. Seems to me, it's more like 50 milliseconds and I can't get my hand off the ON-OFF switch fast enough -- it
Isn't another difference that the SB220 had a 10m position on the bandswitch and the HL2200 didn't? -WB2WIK/6 "Success is the ability to go from failure to failure with no loss of enthusiasm." -Winst
Hi Vic, same probably goes for the HL-2200. BTW I see by my logbook we worked on 160m CW the other day...right about the same time I snagged AH3D. C ya on top band again. -Steve, WB2WIK/6 "Success is
Besides the Coax-Wax, don't forget dB Grease. I used to sell it by the jar. Makes the electrons slip through faster, and if you use enough of it, your coax will actually have gain instead of loss. Ho
[Steve Katz] Low cost, 500W and solid-state multiband don't go together very well in the same sentence. I'd go for the Ameritron 600W SS amp for 1.8-30 MHz, and two separate 160W amps for 50 and 144