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Showing posts from March, 2021

EFHW antenna and the dodgy 49:1 Unun

You might remember the 49:1 UnUn I had built on a small cardboard box. (Actually I might not have blogged about that, I'll do a post later).

Successfully tested on Saturday. Two contacts under 10 mins, then we got cold and walked back home.

9m pole, 10m of thin wire, couple of metres of counter-poise, SWR was 1:1.5 or better at 14MHz. 2.5W to it and we bagged two contacts right away.




Remote operation with FT-847

Well, not bad.

I put an ethernet cable around the study reaching out to the radio, plonked a cheap USB sound card and the Pi, with my old USB to Serial adapter into it and voila, it works with VNC quite well, CAT and the lot.

There are future experiments to be made, like using something faster than VNC but it works, apart from 6m. 

At 6m the cables are getting interference and the TX'ed signal is horrible. Needs more investigation. 

Other thing to look into is the audio cables, right now they are electrically connected. That needs to go, all of that cable stuff needs to be replaced with the audio/TTL connection kit I'm working on. That'd give me both octo-couplers for the serial side and also audio transformers on the other side. Anyway, we'll get there.

It's been a while... Summary of the last 4 weeks

 Well...

Things did go wrong, things did go right.

I built a kit. This is a 100W linear amplifier, but I haven't plugged it in yet. I have a radiator block for it, but I haven't drilled any holes yet. I picked up a beautiful manual hand drill from a Freecycler and I'll be drilling it today, I hope. 


Then I managed to compile WSJTX, JS8Call and JTDX on my Arm laptop and made it work. This was a big step. 


There is a problem with the WiFi chip, i.e., it doesn't work because the kernel is a custom kernel by some guy w/o very good build steps so I can't compile it again easily, and the modules I can strip out of elsewhere cannot be loaded in. It's a bit crap tbh, but it does work with a USB network cable. I have a Dell dock station which functions but then it has only two USB ports. As I type this it is running almost the latest source of WSJTX on 20m, capturing things. I've managed to make more than a handful of contacts on it.

After that I started to build a Raspberry Pi station with software I'd need so that I can plug it into the FT-847 and work on it remotely from the couch. Ouch.

Totally borked...


... Some cursing and soldering later...
  

So this is how it started to look next to my couch - no place to put any snacks or coffeeeeeeeee...

When the weather got better, we started to have portable work, as a part of the exercise. 

"It's cosy here"

We met a lot of friends on the way.



I also dug out my 70cm ZL Special yagi array out of its hiding hole and finally wired it up. This is before, and there's no after picture. I made a mistake and the cross wires were a bit too short so SWR is high but still usable, I will re-do it if I find the courage because it was a very fiddly and frustrating work. I cannot believe the instructions on how to wire on the net don't exist as a nice little picture. Words don't work when you're dealing with this kind of crap. It was frustrating. I had other problems as well, when I was doing a little kit soldering and it drove me completely nuts. After that I didn't touch the radios for a couple of days because I was so frustrated. 


Meanwhile I plugged the tuner back onto the FT-847, and ordered a nice little QRP manual tuner from China - it has arrived now but I'm simply afraid of starting the kit. 

10m is dead, Jim.

Then the company gave me a gift, which was turned into Amazon vouchers, which turned into this little neat thing. It was slightly more expensive from elsewhere but it was the easiest way of getting via the vouchers and as such gifts are, free money, wasted away! It works very well with the FT-818.


I also got myself a fishing backpack based on some ideas from a fellow amateur on Facebook. Now I had used this on my previous hike with the MFJ, but this time I took the LDG tuner and everything fitted in perfectly. The below is with the Watson 9-bander antenna with a single wire working as the counterpoise, and the ground is simply lousy - but it worked! We also managed to make a 2M FT8 contact using the rubber-duck which was amazing.

This is all packed status, perfect although there's only a small amount of space left for a sandwich. One bottle of drink allowed on the side pocket. I am thinking of carrying a spare bag - I have an old gas-mask bag and there are some lovely ex-mil bread bags on Ebay which should be perfect for a sandwich + snack.


Once the restrictions started to allow recreational outings, we could also find a bench and do some FT8 work for slightly longer periods. I spent close to an hour here doing a handful of contacts. It's early days yet, I yet to optimise everything.

Unfortunately the bag has a tendency of toppling over because it had become a bit top heavy, but the Sheep comes to the rescue!

Overall it was one of the best weekend days I had this month.

Also lately I started to cycle because it's feeling warm enough, although no HF work. Only to the shops and back - and the sun still sets quite early, the below is from a cycle back from the shops and it was quite dark now. Also my bicycles don't have any lights - I've ordered some from Ebay, yet to arrive.


This is the Peugeot Pantera bike I have, converted to a straight handlebar because I can't cope with all that bending. I'm still heavy as fuck but I love cycling, even though I can't do even simple inclines right now. As can be seen I had the Baefong with me during the cycles but this was not optimal.


So attached the shopping basket which had been sitting idle in the garage for four years onto it. It doesn't look cool but much more functional. Now I can do both shopping and radio stuff on the move.


Overall March wasn't a very good month for me. Stress levels over the top, and I felt depressed quite a lot. It's been exactly a year since we've got COVID and recovered, and over 3 months my weight loss has stalled and I gained a couple of kgs back and it does feel like it. 

I spent a fortune on my teeth, dentists are way too expensive in this country, plus the gadgets. I've been spending a lot on Ebay buying connectors, cables etc., for various projects but the projects don't move forward. Overall I'm in a bad mood because the life, universe and everything.

The April should be much better. At least my sheep were a big help. Here they are rushing me to help me with a bad time.