r/amateurradio

I'm currently working on a rugged outer cage rail system for the Anytone AT-778UV and planning to expand it to other units. Looking for some feedback.

The core feature is an integrated PIcatinny rail mount system across the top and sides, designed to let you attach modular accessories and build out custom rigs.

I'd love to get some feedback from the community on what you actually want or need in a setup like this. This is optimized for a go-bags but also works very well as a desktop unit.

What modules or accessories would be most useful?

What layout features matter most?

I like the idea of making it modular adding some base functionality to add packout feet and attach it to my packout boxes.

Appreciate any feedback.

Thanks.

I GOT MY G90!

Grinding to Get better at CW Decoding by ear RN

I’m good at transmitting around 25wpm max before it the sentence gets accidentally butchered very often

BUT

The most exciting part is getting to use digital modes for the first time!

(Rtty on 10 meter will most likely be what I’ll try first since it’s near the only hf permitted digital mode for my class & I have previous decoding knowledge on almost all mainstream digital modes, ft8, packet, aprs, sstv, etc.)

But I’m going to go for that generals hopefully Very Very soon!

PS, I Call CQ on 10M SSB Every now and Then see if you can hear me by chance!

I’ll see you on the air!
Where technicians can be
This is KF8GFW
73!

I have this 9 element Yagi and I don't know how to connect the dipole to the coaxial cable. What to put in between the dipole and the coaxial socket.

This circuit was published in the Polish magazine Świat Radio (No. 7, 1997). An LM386 can be used for the audio amplifier stage. A single coil can be wound for your preferred frequency band.

Hey all! I'm pretty new to amateur radio - and was incredibly excited to see that ARISS was hosting an SSTV broadcast event! I was able to capture 3 passes over my location and am incredibly proud to have done so. I used an AR-5RM and an AR-771 VHF/UHF antenna!

I didn't account for doppler shift or anything with these attempts - but think they turned out alright for the first time!

This was a BLAST and I cannot wait to learn more. Hope you all had fun collecting transmissions as well! 😄

I acquired several of these connectors over the weekend at an estate sale. They are N male to N female, but there’s one unique thing I’ve never seen. The halves thread together and the female side isn’t just a barrel connector; it’s got a solid center conductor that slides into the male side. There’s a locking ring on the outer part that makes it look like it’s tunable to optimize SWR. Is this a common connector? Anyone know what the part number is? I’ve never seen these before.

Thanks in advance!

An update to my earlier post about receiving 2.4 GHz with an ESP32-S3: it **transmits** now, too, and the whole thing is a proper release.

**Receive.**
`espdr-rx` turns the board into an rtl_tcp server (1.84 to 2.79 GHz, 250 or 333 ksps, no FPGA); SDR++ and GNU Radio use it as an RTL-SDR.

**Transmit.**
`espdr-tx` sends narrowband FM or SSB voice in 2320 to 2450 MHz from a WAV file, a pipe or a sound card. The chip has no I/Q input, so the trick is polar modulation: the Wi-Fi PHY's test-tone carrier is steered in frequency (the RF PLL's sigma-delta word, 40 000 updates per second) and in amplitude (a gain code,
0.28 dB steps over 18 dB), computed on the PC from the analytic signal of the audio. Screenshot: SDR++ with a HackRF on a second computer receiving the SSB
voice from the ESP32-S3 (that is the
*only*
transmitter).

Measured with a PlutoSDR: with the SSB carrier fully suppressed the unwanted sideband is 61 to 63 dB and the third-order intermodulation 33 dB below the wanted tones. Speech is understood
in FM and SSB, from a file and live from a microphone, for 20 to 30 s at a time without an underrun.

**Honest limits:**
one board, one host (Linux), tested with a PlutoSDR and a HackRF. The power is not calibrated (an estimate: microwatts at the antenna of a dev board), harmonics and
spurious emissions are not measured, the frequency is as good as the board's crystal (mine is +5.4 ppm off; `--ppm` corrects it). It sends only in the 13 cm band and needs an amateur
licence, which the tool asks you to confirm. Much of the code and the documentation was written with Claude as the coding assistant; every number in the docs was measured.

It stands on eSpDR by **h0m3us3r**, who found how to read the chip's undocumented I/Q dump path (thank you!).

Repo and release (the wheel contains the firmware, `pipx install` is enough): https://github.com/jochenhammes/esp32-sdr-trx - https://github.com/jochenhammes/esp32-sdr-trx/releases/tag/v1.0.0-rc2.
How it works and all measurements: `docs/internals.md` and `docs/research/TX-RESEARCH.md`. Reports from other boards are very welcome.