M0RVB (294)

M0RVB

Zigbee

I have always dabbled in home automation, pretty much since before it even became a thing. Most of the control was, and mostly still is via X10 devices and controllers which use mains signalling. This is rather old fashioned now and, being mains signalling is susceptible to interference. At one stage the outdoor light, which are controlled via an X10 appliance module in the workshop were very intermittent, until I discovered the wall-wart on one of the internal cameras was injecting awful noise that caused a scanner AM to buzz wildly when held near any mains outlet in the house! Anyway, that isn’t radio related, but this is… enter Zigbee. I have not read very far into this yet but it uses 2.4GHz among other frequencies for its signalling and there are lots of modules available. I plan to change our two dimmers to Zigbee and it will be pretty much plug and play. Apart from removing the mains signalling path the modules communicate both ways, so the controller can see their status as well as control them. Some of the newer X10 modules do this but very few of them and none of the ones I have. The current…

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M0RVB

FT8 on the FT817

I did a bit of experimenting today with WSJT-X on the Mac and using the FT817. So far, so good. Ok, no surprises there, lots of people are doing the same thing! This is part of my master plan (I'm up to Plan G so far I think) which involves using the FT817 for VHF / UHF instead of the FT450D and transverters and switches, and being able to take the kit elsewhere, either in the UK or abroad. The only laptop I have is the rather old now 2013 MacBook Pro. Still my workhorse for just about everything, I tend to run it plugged into power and with an external monitor. But the battery still holds up for a good while. I wanted to get a Mac Mini because I always use the laptop with the screen closed, using a wireless keyboard, trackpad and mouse, and wired Ethernet. Mostly it works fine, just sometimes it manages to jumble the size and position of all the windows when logging into the thing. No biggie. But used 2018 Mac Minis cost a bunch, so I'll stick with this for now. WSJT-X went on just fine - again, no surprise there. On…

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M0RVB

FT817 upgrade

I plan to use the FT817 portable but also for VHF and UHF FT8 and other digimodes, so I wanted to upgrade the standard oscillator to the TCXO version (Yaesu's TCXO-9). But these are scarce, at least in the UK. I've searched for a while and got nowhere so I ended up buying one from Wimo in Germany as they had them in stock. The original TC1 unit (left) and the TCXO-9 (right) are, of course identical in size and sit on 7 pins. There are at least two variants of the TCXO-9 and I guess this one is the newer of the two. The unit is easy to install. Obviously - or it should be! - disconnect the battery, wear an anti-static bracelet or take appropriate measures, then the old unit simply pulls off of the 7 pin connections and the new unit presses in to replaced it. With the set back together and given a little time to warm up, and set up for CW it holds steady just 2 hertz high. That should be good enough for data modes!

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M0RVB

QO100 DATV reception finally

Well, that made quite a difference! I removed the POTY from the QO100 dish today and replaced it with a 'Bullseye 10kHz' LNB sourced from Amazon and advertised as a 'QO-100 Bullseye TCXO LNB'. It's just clamped in place with no attention to position or skew. Winterhill plugged in and instantly I see pictures. The LNB behind the POTY only managed negative values in the MER and D fields, this one seems too work rather well. No idea what happened to the old LNB but these things happen I guess. It's dry and had a waterproof housing. I've used the existing CT125 cable and connectors. Now to put the Winterhill box in a better location than just sitting on a ladder tied on with a bit of wire!! The above photo shows the Winterhill viewer and console on the left and the Quick Tune on the right, all working nicely.

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M0RVB

QO100 next steps...

As I said before I want to use an actual transceiver for QO100 work rather than the Pluto. A precursor to that is a 2400MHz transmit capability and so I now have a nice new (used, new to me) SG Labs 13cm transverter, complete with the PCB log periodic antenna. It is already set up for the correct frequency range and seems fine... so, the next step is move the dish, clear the loft in that area, and get the kit up there. The transverter claims to put out 2W so I can use the existing AMSAT UK PA via an attenuator (max input is 200mW) which should get me 4 to 5W to the dish and has been adequate in the past when using the Pluto. I will first try with just the 'raw' 2W and see if I can get into the satellite. The eventual aim is to use an 80W PA I have ready so I can use DATV as well as SSB or digimodes - that also takes 200mW input - but as yet I don't have a suitable PSU.

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