70cms fail…

Seeing there is a 70cm FT8 competition on tonight I sort of threw kit together to see if it even worked. So, one big wheel (‘big’ on 70cms is hardly big!) and a transverter plugged together and I managed a few decodes. Good, but…

It fell apart once I tried to answer a CQ. The caller was high on the waterfall and the amount of drift the blessed transverter managed after just one transmit cycle moved the received signal right off the right hand side. So that failed.

I did try to answer one more station that was in the middle of the waterfall but the same happened, this time still on the waterfall but no amount of chasing it across the screen yielded a decode. Fail again.

Apologies to those two stations, this transverter is clearly useless for digital modes but I thought it worth a try. A tad disappointing. I managed all of 14 miles – I think the transverter manages 10 watts. I can do 17 miles to the local 70cm repeater on a handheld and supplied short antenna on 5 watts FM.

ISS SSTV April 2022

Two events this month, the first from the 7th to 8th and the second from the 11th to 13th (ongoing as I type). I received nothing at all on the 7th and a few poor or very poor images on the 8th.

On the 12th I received one reasonable image at 13:29 UTC and an incomplete one at 15:06. I even received a partial image at 16:36 with the ISS mid-Atlantic. That probably had the benefit that this area is clear to the horizon roughly in an arc covering Wales the lower half of Ireland.

No more passes here until tomorrow… let’s see what happens.

Knobless FT2D

A minor disaster befell the FT2D, the tuning knob fell apart. Part of the inner plastic bit that holds the metal D-shaped ‘grip’ (?) that fits it onto the shaft broke away and the knob dropped off. The radio has never been abused…

Googling (actually, duckduckgo’ing, is that a thing yet?) finds a few people have created 3D printer files for this which suggests it may be a known weakness. Now, where is that 3D… oh, wait, it was on my Christmas list but Santa never brought it. Drat…

For now the bit that dropped out has been glued back in with some slivers of matchsticks as padding to hold it together. So far, so good.

Projects, projects…

So, my projects remain stalled… no idea where the time goes! I seem to be amassing bits for projects but they are just piling up. Thus far the Portsdown is still needing filters and PAs. I have a VLNA for 23cm to build. I need to move the QO100 dish from the back of the garage onto the house wall so I can mount a PA and transverter setup close enough to the shack to be able to use a transceiver, and finally get onto the wideband transverter using the Portsdown. I have dishes for higher microwave bands, a 10GHz SSPA, a 2.4GHz PA and more microwave bits coming soon including a bandpass filter for 23cm and some microwave relays.

Now the weather is improving hopefully I can make some progress. I need to get a mobile tower so I can do various pointing around the house (surprisingly I am actually qualified to build these things!) which will make it easier to move the QO100 dish as well as finally getting some antennas outside. But house DIY comes first, all else is secondary…

Check back this time in, umm, maybe 2025!

ISS SSTV tests February 20th 2022

Two pics from today’s ISS SSTV test…

This is a screenshot after the fact, I was not around to witness it. The ISS had already moved out of range for me by the time I got to the PC (ok, by the time I woke up!). I was there for the next one at around 10am UTC. The signal came in strong at first but faded out very badly after a few seconds, and then faded completely out after that so it’s not much of a pic.

These are received on 437.800 and given my internal collinear struggles a bit to receive the SSTV images on 145.800 it is probably not surprising that this UHF digital test faired worse. But the blocks that make it through are nice and clear.ss

APRS fiddling

I’ve had a Yaesu FTM100DE for a while now and for all that while it has had a USB adapter plugged in and doing nothing. The adapter, SCU-20 came with the transceiver. Anyway, I wondered what it could be use for. The handbook discusses it being used to extract GPS data and packet data and a quick search found some software, APRSIS32 for Windows (see http://aprsisce.wikidot.com ) that talks to various transceivers.

So, software loaded, I needed a driver from Yaesu. Here’s where it begins to get a little tedious as those of you who have had to go looking for drivers will no doubt know. First port of call was the Yaesu site and a search for FTM100. Ok, found that. Now ‘files’ and … a driver for a SCU-19. Searches for SCU-20 found a PDF which contained the filename of the driver but not the source. I eventually found it… under the files for the FTM400.

And that was the hardest part. Driver in, USB lead connected, APRSIS32 loaded and a few parameters configured and there is it.

The software will also send messages etc. but apparently Yaesu do not allow their kit, or at least the kit I have send data out from sources that are not internally generated. (ref: https://groups.io/g/APRSISCE/topic/76092175 ) Oh well, I didn’t get the radio for APRS anyway but it’s a bit annoying.

Anyway it was a fruitful ‘have wire, must make it do something’ episode. The APRSIS32 software is neat and full of functionality, and quite intuitive. It also has a whole support group on groups.io.

10GHz experiments

I am slowly getting kit together for 2.4GHz and 10GHz. So far I have SSPAs for both bands, one which will hopefully enable me to get onto the wideband DATV part of QO100, and the other as part of a 10GHz setup.

I got a Goobay LNB from eBay a while ago. My plan for this was to build it into a POTY for QO100 but I acquired a ready-made POTY that had an input for a 25MHz clock signal and that all works fine. So I wondered if this LNB could be persuaded to receive 10.368GHz. Fortunately I had not got as far as pulling it apart. The LNB is marked 67321, input range 10.7 to 12.75GHz, local oscillator frequencies at 9.75 and 10.6GHz.

Reading up on LNBs in general was advice that one can use the 24th harmonic of a 70cm handheld held in front of the LNB to generate a 10GHz signal. This I had to try and with a bias-tee feeding 12V to the LNB and an SDRPlay RSP2 and SDRUno it does in fact work.

Transmitting on 432MHz should have, in theory generated a peak at 618MHz on the SDR (10368 – 9750) but it actually came out at 618.6MHz. Well, close, and at least it is something. I checked the radio output on a counter which showed 432.0018MHz. I also checked the SDR receiving 432MHz and it showed it correctly.

So the LNB is not quite there but this was only a quick test and it does show the way to test my eventual transmitter actually transmits.

The next step is to assemble a 10GHz transverter and the parts for this are hopefully on their way.

A little bird told me…

Yeah ok, naff title. A new toy arrived today, I’ve been thinking about getting one of these for a while now and not doing anything about it. The lack of accessible (i.e. ones not too far away) radio rallies puts a damper on acquiring stuff so this was an eBay find.

The meter had no slugs but I had ordered a couple from Vintage Electronics as well and all arrived at the same time. Of course I had to test it having never used one before, but as my radio’s and patch leads are all currently PL259 I had to use an adapter. Actually three adapters! I ended up going from the rig via an SO239 to BNC male, BNC female to SMA male, and SMA female to N male! But hey, it works. And yes, I really do intend to convert to all N type connectors here… I even have them ready to make up. Lazy…


So… having an Allstar node I wanted to configure it for Echolink. It seemed this was just a matter of editing the pre-prepared configuration file echolink.xxx and renaming it to echolink.conf. Edits in place, this I did. Oh yes, and I set our broadband router up to forward the relevant ports to the hub. On restarting asterisk it gave numerous errors of the form ‘Error in parsing header on servers.echolink.org’. Hmmm.

Ok, scratching around the web I found that Echolink has a firewall test service at https://secure.echolink.org/pingTest.jsp. It failed. Ugh.

Then it dawned on me (meaning I read the documentation a little better!). I had set a callsign with ‘-L’ at the end which appeared to be the way to go. But this needed separate validation! Once that was done it all sprang into life.

Simple, and also obvious when I realised. Old age?

http://km6uso.net/index.php/2021/02/27/adding-echolink-to-your-allstar-hub/ is an excellent guide – there are others of course but this one pointed out clearly the need to register the -L or -R callsign.



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