** A DO-5 case 3A rectifier dissipates c. 2.2W at 3A. Since rectifier junctions typically have higher allowable junction temps than zener junctions, running a DO-5 case zener at 4.5w is bananas. - R.
This sounds like a workable solution, Bill. However, a Bruene neutralization bridge might be useful improve stability as well as input swr above 40m. [Fig. 5 on my Web site]. cheers To: <amps@contest
The problem with a 50w zener is that its Vz is not adjustable. A fwd-biased Si diode string can be adjusted by changing taps. - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/measur
Fwd drop varies little between 0.2A and 1A in a Si junction. Henry Radio Co. amplifiers have used fwd-biased diodes for years. I have used fwd biased diodes for over a decade in a TL-922 and a SB-22
Henry Radio Co uses fwd bias diodes to set fil-cathode bias in it's amplifiers. Is there a zener made that can take a 400A glitch? - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/
The Semtecc diode string in question appears to be a 10 diode unit. Yes. 6V sounded a bit high, so this morning I tested a 1n5408/3A diode for fwd V-drop using 8877-sized currents, assuming a ZSAC of
One can tell by tapping the core with a screwdriver. Ferrites are hard like glass or ceramic, and they make a tink when tapped. Powdered iron is softer. Also, some ferrites have resistance and powder
Cuting off the tubes intermittently during speech with RF-actuated bias results in switching rapidly in and out of linear-bias during soft-syllables. For this reason, Alpha 77s are well-known for the
RF-actuated bias switching works as advertised on CW/FM/AM/RTTY. The problem area is SSB. cheerz, Steve - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/measures. end
I am biased toward simple, minimal-cost, glitch-resistant circuits that work. The [Figure 7] optoisolator/10A, Si-npn switch/3A diode-string will reliably handle a 3cx3000A7 and it switches in under
** At this QTH, the hotter the junction gets, the lower the Vf. Try some espresso. go - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www.vcnet.com/measures. end
Interesting discourse, John. // A Hughes employee told me that their 100kW HF amplifier used some Ni-Cr conductors in the output enclosure to reduce VHF amplification. - Instead of using Ni-Cr in a H
Cr is a sustantially better conductor than Ni-Cr or Ni-Cr-Fe. At 50MHz, Ni-Cr has about 5.5 times as much RF resistance as Cu. At 60Hz, Ni-Cr has c. 50 times as much resistance as Cu. - R. L. Measure
What is the cost in quid [£] of the TL431-TIP147 circuit ? What is the I-peak withstanding ability of TL431-TIP147 circuit? cheerz, Ian - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K, www
I knew that the story about 6v bias variation was unsliced bologna, so I measured the result of Si junction Vf with a 0.1A to 1.2A current variation. And Henry Radio went to the more rugged fwd-bias