iiinova — where your digital self keeps evolving

2ftg.bsky.social @2ftg.bsky.social · 04/07/2026

Back in the day this payphone needed two of these payphones at minimum for a phone call.

A close up image of the sticker on the payphone front:
MINIMIMAKSU 2MK
MINIMIAVGIFT

In front of that one can see a pair of Knipex pliers holding up a muted gold color one Finnish Markka coin.

2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

This way one of the ports stays original and can be used to feed power to the LNB. While the other two will output the RAW IF from the MXL803.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

As I cannot control the MCL862, I bypassed it.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

The IF is delightfully wide.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

Here's some bad graphs about the two ports. The horisontally polarized one seems to have 10.400 GHz LO and the vertical one seems to have a 10.000 GHz LO.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

And get the downconverted RF out.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

Let's feed it some RF. The 3rd harmonic from the ADF4350 synth is plenty strong. Hell, even the 5th one is. As I used that and a homebrew version of this in the past to align one 19GHz LNB to 20GHz.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

Even without any commands, the MXL862 does something.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

Instead, I soldered in some wires and gave it power.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

There is no control bus, it is just all strapping resistors apparently. So far I have not bothered to map out it's connections that much.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

The LNB side of things is managed by yet another MaxLinear chip without public documentation. An MXL803. It seems to be a dual down converter with all the frontend bias control and charge pumps for pHEMT biasing integrated. It uses a 50MHz reference oscillator here.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

The large blobs connecting the IF from the downconverter to the MCL862 are hilariously large. The middle DC pin is 1.8V supply to the LNB end of things.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

The ports look mostly the same. Except port 1. Which has some additional LC-filtering on it. I suspect it is the nominal control port, to which the FSK commands for the MXL862 get sent to.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

The output then goes into a 3-port splitter, seen here in the middle and goes to the three output ports.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

This MXL862 chip does the digital magic. A "Full-Spectrum Capture ® Satellite Digital ODU IC" The two LNB IF's just get digitized by it. In full. And then gets DAC'd back out to 950 MHz - 2150 MHz.

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2ftg.bsky.social @2ftg.bsky.social · 08/04/2026

New day new LNB. This time a Digital Channel Stacking (dCSS) one from Canal Digital. It digitizes both polarizations and then puts the requested channel at the requested place in the down link. Too bad the MaxLinear MXL862 has no public documentation. A quick teardown thread

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2ftg.bsky.social @2ftg.bsky.social · 10/02/2026

Another board from a module. With some Sprague made 2N2219A. 7401 datecode.

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2ftg.bsky.social @2ftg.bsky.social · 09/02/2026

It's a TUV 2132,2 of a Nokia TU21000 series FM12/24-400 link.

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2ftg.bsky.social @2ftg.bsky.social · 09/02/2026

Here's the bottom of that PCB.

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2ftg.bsky.social @2ftg.bsky.social · 09/02/2026

Inside a plugin module from an Ancient Nokia radio link.

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2ftg.bsky.social @2ftg.bsky.social · 20/04/2025

And no, it was not on the first try.

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2ftg.bsky.social @2ftg.bsky.social · 20/04/2025

Ya recon that's the UART TX pin?

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2ftg.bsky.social @2ftg.bsky.social · 11/04/2025

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.

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2ftg.bsky.social @2ftg.bsky.social · 30/03/2025

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

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2ftg.bsky.social @2ftg.bsky.social · 27/03/2025

Here's another angle of it in use.

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2ftg.bsky.social @2ftg.bsky.social · 09/03/2025

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?

Picture shows seven rack mount devices.
Three 2u Avaya G430's are piled on a chair with a helixal 1800Mhz antenna under it and a SmartStore box with a threephase plug in it.
Four 4U or 5U Avaya G450's stand on their side next to it.

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2ftg.bsky.social @2ftg.bsky.social · 01/03/2025

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

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2ftg.bsky.social @2ftg.bsky.social · 01/03/2025

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.

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2ftg.bsky.social @2ftg.bsky.social · 01/03/2025

Added a quick Meshtastic node at the OH2TI radio club with some donated Lilygo TTGO boards. #Meshtastic #PRK #OH2TI #TTGO #LoRa

Picture shows an antenna improvised from a circuit board cutout on a large circuit board ground plane.
It has a piece of paper with the nodes information attached to it with some painters tape.
Paper reads Meshtastic @ 868 (crossed out web ui text)
PRK2
OH2TI-PRK-MESH2

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2ftg.bsky.social @2ftg.bsky.social · 09/02/2025

Also forgot just how slow it was to install stuff from a CD to a spinning disc. Both being on IDE as well.

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2ftg.bsky.social @2ftg.bsky.social · 09/02/2025

Just some retre things from the archives. Fun to run the higher end version of the mobo I had in 2004. #Retro #Athlon #win2kpro

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

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.

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

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.

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

The now unused output of the 30dB power attenuator I terminated.

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

There we go, predriver output tapped. As the clubs CMU200 has the high power input option, I wired it directly to it's input.

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

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.

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

-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.

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

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.

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

POINT9 PAG-5 --> PAG-5 -> Motorola XRF186 in this thing. Active-ish bias with over drive protection via a single LM741.

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

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

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2ftg.bsky.social @2ftg.bsky.social · 02/02/2025

The absolute chaotic energy. From top to bottom on the left: - MMIC's and other GHz - Miniature valves -NAILS

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2ftg.bsky.social @2ftg.bsky.social · 27/01/2025

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.

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2ftg.bsky.social @2ftg.bsky.social · 27/01/2025

Closer up of the BK4819 and 21.4MHz xtal filter.

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2ftg.bsky.social @2ftg.bsky.social · 27/01/2025

On the back, showing the MVsilicon AP8048 MCU, BK4819, BK4829 and the 21.4MHz crystal filter from the suspected HF receive side. Looks like two low pass filters on this side, so the images might be of the 6m/2m/70cm triband TK11(8).

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2ftg.bsky.social @2ftg.bsky.social · 27/01/2025

Some more Quansheng TK-11 images dropped. This time of the internals. The images seem to be of the triband TK-11(8). Thanks for Dimitar Milkov for bringing these images to my attention and Silent YANG for taking them. #Quansheng #TK11 #hamradio

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2ftg.bsky.social @2ftg.bsky.social · 24/01/2025

Also, the RF transceiver for the TX side is likely BK4829, due to the upper RX range matching the datasheet exactly. 1160MHz for BK4829. 1200MHz or 1300MHz for BK4819, depending on what year your datasheet is from. Can't wait to see some teardowns, or if the price is right, doing my own.

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2ftg.bsky.social @2ftg.bsky.social · 24/01/2025

The 6m/2m/70cm tribander also has the same wide receive, just lacks 25-29MHz TX. Thanks for Doofenschmirz and dr inż Mario on the Quansheng UV-K5 developers Telegram group for bringing these to my attention.

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