For those not needing another project, just buying a temp controlled soldering iron might be an option. There are complete kits that use the Hakko style irons for around $25: https://www.ebay.com/itm/

Tom, > As a fun project I wonder how well this would work to control the temperature > of an old generic soldering iron I have laying around. Building some kind of > circuit that can switch the AC vol

The IRF510's would be quite happy with 16.8v, and would operate with less distortion for the same power out than they do at 12v. But you would need a 12v regulator such as the LM2940T-12 on the main u

Mike, You apparently have this thing: https://www.astroncorp.com/linear-desktop-w-meters https://usermanual.wiki/Pdf/ASTRONRS35mPowerSupplySchema.237106077 Looks like a very nice 25 lb linear supply.

The move to an 11.059mhz IF was done to avoid a beat note from the 16mhz processor clock. https://groups.io/g/BITX20/message/63636 https://groups.io/g/BITX20/topic/ubitx_help_strong_audio/8872690 The

The primary advantage of having separate 12v pins for the main uBitx supply and the IRF510 drains is that we can easily disable power to the IRF510's when debugging all other parts of the transmitter.

Banggood is a good place to buy Chinese electronics. Perhaps an ARM processor board, a buck switcher, an LCD display, an AD8307 breakout board. Buffers you somewhat from the full on Aliexpress experie

Not a bad idea to have a box in the corner that all such packaging gets thrown into. I've ordered dozens of items from Banggood, one was an ESP32 breakout board with camera, but it did not arrive with

As Reg suggests, things can go wrong. Wear eye protection, and put a fuse in series with your power supply. I recently ordered this thing from the Banggood US warehouse (price jumped up by $13 after I

On the Antuino, audio could be taken from the existing ADE-1, with some amplification. Or we could add a a second mixer after the crystal filter. On the TinySA we could also just take audio from the f

Farhan, Interesting, good post. Unexpected that a pure resistance can contribute to IMD. I had always assumed the primary issue would be that a graph of Vgs vs Ids was not a straight line, but you giv

A direct conversion receiver consisting of just a VFO (perhaps an Si5351) and a mixer (perhaps a diode ring) could send audio out to the soundcard of a computer for spectral analysis. That would be su

Yes, IMD does not matter if you only transmit one tone. IMD has to do with two signals combining in a non-linear manner, when they don't just add together like they should. When testing a wideband lin

David's answer is right enough. Another way to look at it, what really matters is the winding ratio between primary and secondary. However, the number of turns matters in that you don't want so many t

Hey Jack! You got a bite! http://www.arrl.org/shop/Microcontroller-Projects-for-Amateur-Radio/ Speaking of books, I'd recommend EMRFD, if you can get a copy. Fantastic book, going out of print, no lon

He tests for IMD using the gear he has, he can't split two audio tones. Should catch most of it. Jerry, KE7ER

Evan, Could be that Marko was not formatting as a FAT32 filesystem as you suggest. However, he explicitly said: "This doesn't work if you format the card on a Mac, as it always adds some hidden files

Except the Mac insists on adding hidden files, even after a reformat. This can confuse the Nextion update, as it assumes only one file on the SDcard. https://groups.io/g/BITX20/message/86252 Jerry, KE

I don't recall this problem coming up before. Any guess what frequency the oscillation is? If you can't state a frequency, compare it to a typical CW tone, or power line hum, a whistle when calling yo

#bitx40help #noise

There have been reports of success in getting more power out of the uBitx by raising the voltage to the IRF510 drains to 20v or so. But this is on some very thin ice. For those seriously looking at go

#ubitxv6 #v6