2ftg.bsky.social
@2ftg.bsky.social
And no, it was not on the first try.
April 20, 2025 at 9:11 PM
Here's the DUT.
April 20, 2025 at 9:11 PM
Ya recon that's the UART TX pin?
April 20, 2025 at 9:11 PM
Shiny waveguide multiplier with a WR-137 flange.
So maybe 5.76GHz target output with suitable Drive.
Currently best output was achieved on ~6GHz with 1.5GHz and 3GHz drive.
April 10, 2025 at 11:13 PM
My first 122GHz band QSO.
VK3CV transceiver with UV-K5 with fagci spectrum as the IF radio.
QSO was with Michael, OH2AUE.
#122GHz #mmW #microwaves
March 30, 2025 at 10:01 PM
Here's another angle of it in use.
March 27, 2025 at 11:40 PM
Rate my PTT.
March 27, 2025 at 11:39 PM
Okay so, one of the local radio clubs got these Avaya things.
Outside of them doing VOIP and that one dude reportedly has two controllers for them, I don't really know anything about them.

4x G450 and 3x G430
Is there anything useful one could do with these?

Or should we just part these out?
March 9, 2025 at 6:35 PM
The node currently lives indoors on the most top most shelf available at the PRK radio club.
This is a very temporary location for it, but it will later go to a better location on the roof.

#Meshtastic
March 1, 2025 at 7:55 PM
The display is a tad borked, but who really cares?
I'll change the role of this node from Client to Router, when I can place it on the building roof with a good antenna and permanent DC feed with the appropriate lightning and RFI protection at both ends.
March 1, 2025 at 7:55 PM
Added a quick Meshtastic node at the OH2TI radio club with some donated Lilygo TTGO boards.

#Meshtastic #PRK #OH2TI #TTGO #LoRa
March 1, 2025 at 7:49 PM
Also forgot just how slow it was to install stuff from a CD to a spinning disc.
Both being on IDE as well.
February 9, 2025 at 5:23 PM
Just some retre things from the archives.
Fun to run the higher end version of the mobo I had in 2004.

#Retro #Athlon #win2kpro
February 9, 2025 at 4:29 PM
Because the XRF186, or at least it's production version, MRF186 I can still source as used pulls on aliexpress.
And those might even work.
The original transistor has a late 1997 datecode on it.
So the Motorola logo on it is legit.
Not that an amp that died in 2005 would have anything else.
February 2, 2025 at 10:48 PM
Now -13dBm drive gives us +14dBm output. A nice gain of 27dB.
I still think this is too low, but our output matching might be severely wrong.
As the point where I tapped it was meant to drive the balun for the push-pull LDMOS final.
I hope this is the case and now one of the PAG-5's being bad.
February 2, 2025 at 10:48 PM
The now unused output of the 30dB power attenuator I terminated.
February 2, 2025 at 10:48 PM
There we go, predriver output tapped.
As the clubs CMU200 has the high power input option, I wired it directly to it's input.
February 2, 2025 at 10:48 PM
The two predriver stages appeared to be functional, while the XRF186 LDMOS transistor had it's gates near ground level, regardless of the bias setting.
So I soldered in a pig tail and connected the predriver output to it.
February 2, 2025 at 10:48 PM
-27dBm drive on 100MHz gave us around -52dBm on the CMU200.
With the 30dB attenuator in between this means we get -22dBm output (ignoring the losses in the RG58 patch cables used) with -27dBm.
A huge 6dB of gain in that thing.
As already known, it's a bit dead. But not 100% dead.
February 2, 2025 at 10:48 PM
Added a 30dB 100W attenuator in the output and tested it.
Idle it took 1.03A from the 26V supply.
With it in shutdown it took 0.26A, which likely was the fan.
February 2, 2025 at 10:48 PM
POINT9 PAG-5 --> PAG-5 -> Motorola XRF186 in this thing.
Active-ish bias with over drive protection via a single LM741.
February 2, 2025 at 10:48 PM
Rated to do at least 50W from 20MHz to 512MHz and do that while being VERY linear.

Guess what, it's dead.
A quick lil thread about it.
#surplus #GHz
February 2, 2025 at 10:48 PM
The absolute chaotic energy.
From top to bottom on the left:
- MMIC's and other GHz
- Miniature valves
-NAILS
February 2, 2025 at 7:47 PM
Close up of the AP8048 MCU and the RDA5807 FM receiver chip.

The AP4804 MCU is interesting that is has 128k SRAM and can execute code from SPI Flash, so if it is possible to get custom code running on the radio, the program size should not be a major worry.
January 27, 2025 at 11:29 PM
Closer up of the BK4819 and 21.4MHz xtal filter.
January 27, 2025 at 11:29 PM