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Apologies if this off-topic question is too far out for this group. If so, please delete and ignore. Looking for DIY construction project References? or? .pdf's ? in QEX or QST or other , for

DaveD is probably a chatbot :-(

I'm the owner and I have no idea who is doing this or how to contact them. None of it makes any sense. Reg

I have no clue who DaveD is am NOT happy. Reg ----- Forwarded Message ----- From: Group Notification <[email protected]>To: Reginald Beardsley <pulaskite@...>Sent: Monday, June 19, 2023

Been reading QEX almost from the beginning and have enjoyed all my issues. I also have a fairly nice technical library. I have a question which I've never seen an article on and I wonder if some of

Hi Jim, R8/R9 seemed to reduce the ringing, but I never proved this definitively. The symmetry adjustments were included as a "just in case" feature, but I never did any further work to determine if

WRT my third question, I just figured out that the RC time constant of Q1's gate drive provides a soft ramp for the PA. -- JimC (KQ7B)

Jeff, Your 80m amp inspires several questions... * Is the purpose of R8/R9 to protect U8/U9 from excessive peak current, or to mitigate ringing, or...? * Did you find the symmetry adjustment (R3/R6)

I was able to pick up a CW filter for my TS-520 and ran a series of tests using my 8593A SA w/ TG. The photos show the "matching" network and the spectrum for cases I've tested so far. Next up are

Jim, I built a push-pull class-E amp some years ago (for driving an 813-based home brew AM rig). In case my own experiences might be useful to you, my notes can be found via the link below. Building

FWIW I am currently working on measuring and sorting 500x 5 MHz HC-49S crystals into 10 bins based on Fs at 0 C and then sub-sort into 10 bins based on Fs at 50 C drawing the crystals from a water

My Class-E amplifier (Sokal, Jan/Feb 2001; https://people.physics.anu.edu.au/~dxt103/calculators/class-e.php ; etc) investigation has struggled to find suitable devices for the final and its driver.

Sorry about the slow response. I'm not yet aware that is an issue. I'm still working on the basics, e.g. measuring a Kenwood TS-520 CW filter and construct fixtures. But a tuned choke or two should

Welcome. I'm afraid this list hasn't had much traffic though I'd like to see that change. I started the list as a venue for discussing articles in QEX, but then there weren't any that really

I'm a retired HP engineer and college professor who finally has time for radio projects.? Current investigations focus on POTA/SOTA equipment and digital modes.? My wife and I live on a small farm

We introduced the first SDR based Telemetry system as well. Our analog designs had bandwidths down to 1 KHz, without crystal filters. Have fun, but between my work with Telemetry and Microwave TV

I'm a little confused. How is this related to implementing very narrow filters by using isolated sequential, partially overlapping filters? The Icom 705 will give single signal reception with

I worked with high end Telemetry receivers at the factory. All tuned circuits were Lc or RC. The only crystals were for LO or system clock applications. The LC were aligned on HP Network analyzers. RC

*Everything* about the shape is reflected in every other aspect of the filter. TANSTAFL! One should never design a filter without examining the behavior in both time and frequency very closely. My

It's probably worth noting that the filter passband shape affects group delay. This was noted and illustrated in EMRFD. The rapid transition from a flat passband to sharp skirt rolloff yields some