Do check before applying mains that it will take 240VAC - some U.S. stuff won't. Results in emissions not covered by ICNIRP regulations. 73, Simon

John - sorry, your perfectly reasonable enquiry got hijacked for a bit of frivolity. You might want to contemplate a bit of filtering between stages if you add an extra amplifier. 73,

I don't recall ever hearing anyone calling "CQ one four four point three zero zero Megahertz" On the principle of max info for min bandwidth, "Two (metres)" wins every time. What was the frequency of

I'm totally out of my depth on the RF side, but just a quick thought on the DC end. Any power rail noise may well work through as AM on received signals either directly or by varying the bias settings

A while ago I built two in beer kit tins, 165mm long by 100 dia. Back - back loss less than 1dB, SWR about 1.5:1, according to 4GHz nanoVNA. SMA soldered to can side, Probe 50mm up from bottom, 30mm l

I seem to recall that during a component famine quite a few years ago, availablility was often quoted as 99 weeks. This appeared to be due to only having two character spaces to put the digits in. 73,

A set of un-drill bits would be useful. They could live in the same box as the rectangular hole drill bits. 73, Simon

There seem to be several. "http://www.heywhatsthat.com/profiler.html" Re input, yes, yes and yes. Also you can enter the frequency, although what the resulting envelope tells you I don't quite underst

All received so far (to 12:46 UTC) on HF conical monopole + FT-450D at IO81RD86. 115300 -5 10.9 1573 & G4JNT TESTING 115315 -8 11.1 1563 & G4JNT TESTING 115330 -3 3.7 1558 & G4JNT TESTING 120915 -4 11

Stretching the memory banks to their limit, as a student I spent one industrial period in a lab with many frequency standards, double-ovened crystal and rubidium. 5MHz output was popular, I think they

Thanks, both. The discontinuity correction graph comes from a 1944 ProcIRE paper which can be downloaded from https://worldradiohistory.com/hd2/IDX-Site-Technical/Engineering-General/Archive-IRE-IDX/I

Thanks to Neil G4DBN for his talk on machining, oh for a workshop like that! The filter design spreadsheet from F1FRV doesn't seem to be available, the links are not working at the moment. Anyone have

Thanks, everyone. This was my first post here, so I'm very pleased with the responses. 73, Simon G8DMN

If it is a quarter-wave radius (or anything over the 1/10 or 1/8 wavelength rule of thumb) then it's into transmission line territory and all starts getting rather complicated. There's a lot of confus

Hi, Looking at various microwave PCB layouts, I see small quadrant shapes half-way along thin tracks feeding DC to amplifier stages. I presume they are capacitors forming a low-pass filter with the in

All sorts of useful PCB stuff here, includes differential pcb traces : https://saturnpcb.com/saturn-pcb-toolkit/ 73