I have continuity in that test step on page 17 between Q1 and right side of C7. If it should be no continuity, what's up? I removed the transformer and it is not shorted and I black marked the

Open circuit.

ajparent1/KB1GMX wrote on 3/7/2020 9:06 PM: Hello-- Hey, I'll take a stab too<g>. Suppose that the RF output transformer core is mismanufactured or mislabeled? Standard practice is to color-code

I can't see. I literally have no idea. I am stabbing in the dark. I gave you information IE, putting in a lot of power and not getting much out. Something is wrong. The fading power if seen

I read again output impedance? Every time I see that it usually big tube amp with a PI or PI-L network that when tuned does an exact match. So the question always seemed rather abstract at best.

Allison, I see continuity there. Should I proceed? That is my question. I am building this second 20 meter amp to see if I get the same result of sinking power.and if it is a problem in the way I

George, We can only guess, even then we are limited to poorly being devoid of values, numbers, or test procedure used. Pictures? The assumption is its a common problem, we all experience it and we

The sentence: "You should see any continuity here." What does that mean?

Assembly Manual page 17. I am doing a complete check on a new board of all my Transformers as I install them to make sure all my connections are exactly as Han's intended them. The bifilar

That's what I like about groups.io anything old will be new again after a small wait. Old info frequently by only days for the email subscriber is often lost information. Its the nature of the

Chris look at the multiple posted in the past. and http://qrp-labs.com/linear.html Down the page some. I'd call your numbers low and generally wrong. That said with the low drive needs (under 50mW,

Curt, Checking would be good. 5A at 20V would be 100W and at 70% efficiency minimum thats 70W out. I did that as a does it makes sense number. Typical input is abut 3.5A at 20V or 70-72watts DC and

Don #HB 😁

Thanks Curt. I'm not too worried about the 5 amp current requirement. If you go high enough on the C rating of the battery you should have plenty of headroom. I'm just curious how hard the upper 22V

Evan the main factor might be the current capacity of those batteries - I recall something like 5 amps may be required? check Hans clear instructions on voltage and current. note the amplifier is a

YLs and OMs, today I performed some measurements on the output impedance of the 10 W linear amplifier. Admittedly, I had to get by with some rudimentary equipment (bunch of different resistive loads,

Thanks Jim, It turns out an individual as offered to check it out for me. If he has no luck, and you are still interested, I'll let you know. Thanks again. This thread can be put on hold for now.

I'm currently building a QCX 50w amp for 20m to match my QCX transceiver. Will a 6S Lipo battery be too much for the amp? The 6s packs are 25.2V fully charged.

“BEO is uncommon except in those white ceramic, and I'd add expensive RF power transistors. “ The very reason for their superior heat transfer capabilities… Dr. William J. Schmidt

Oh yes, totally agree. Running a few milliwatts on a VNA etc is one thing, putting the intended power through something is a different matter (saturation etc). Geoff.. Totally agree. You can measure