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John, thanks for the reply. Answers to your questions: This time it was the same as last time, Q504. The time before last it was Q505. SWR was 1.0 according to my QRP SWR/Dummy load. Current draw on

And I apologize for misspelling toroid. It's been a long week. -Alex AD5MO

Ryuji, You are a fearless experimenter! Kudos, OM! 73 KJ4A wrote:

Rich Evan thanks for the pointers. I’ll have to research the past archive from my desk later I was trying to see the safe limit if the output power the other day by increasing the powe and supply

Ryuji, Evan is correct. The clever voltage doubling reverse bias circuit should prevent that from ever being a problem. The 1N4007 achieves its high reverse breakdown rating by being a true PIN

Cliff, darn, sorry to hear that! Did you note which BS170 blew? Was it same or different from last time? I presume you checked SWR and it was OK? What current draw were you seeing from the PS in xmit?

While at work, I was looking at a photo of the board on my phone I took before redoing the T1, an I just realized that the L12 inductor has a rather sizable slack on the last "turn", as in the wire

Hi all. After initially testing a new QDX on all bands (with erratic RF sweep results), a newly built QDX (5/low band version) now thinks it is 80m only - has anyone ever seen this? I've tried a

Tony, Couple of years ago I built cubesat ground stations with these. They worked pretty good. They are kinda hit and miss but not that off from FCC parameters. It’s easy to tune them just by

Hi John, Well, I hoped it was fixed, but apparently not. Just blew at least one BS170. Had it all assembled, but outside the case. Worked for about and hour of transmit time, most of that on FT8. It

thanks . i will try the Zyyini Low Pass Filter Module. ron kc0tdj

Wow, you can't beat the price! Barb, have you scanned these for harmonic rejection? I'd like to pick up some of these if they meet FCC specs. Tony AC9QY

Find any message from Hans. At the top left of the message, find his name and Left-Mouse Click on it.? This opens a selection box containing "Find All Messages By This User".? Click that. This

Here's an alternate differential 431 MHz design using a 1:1 transformer to handle the differential drive. Tony AC9QY [email protected]> wrote:

I use these: Zyyini Low Pass Filter Module, Power Distribution Control Equipment, Wide Operating Frequency Range， for RF Signals https://a.co/d/chwdtZk These have a pretty good response on 70m. 73

Versus

Hi Ron, Here's an LTSpice model for a filter I designed at 431 MHz that you can easily tweak for 432 MH*z. *This is only a model using ideal components and hasn't been built. If nothing else, it'll

Hi, VDD has a short. Not VCC. A new kit is on the way. Before any soldering I will check. 73, Holger DL9HDA

Hi, D109 is on ps #2. It is not plugged in. 73, Holger DL9HDA

I broke the BPF inductor into two cores and see no deep notches but still see second peaks in all but the lowest band 60/40m in my case. If you suspect your rig has less than perfect t/r switch fet,