More Solar and Battery Power.

Last year I got a couple of 24V/100Ah LiFePO4 batteries and the plan was to use them as power supply for 24 - 28V power amplifiers, and as extra capacity for my two older 12V/100Ah batteries.

The 12V system has been used with 3x 100W solar panels, and has supplied a few radios with power in the period from mid February until beginning of November last year. In the dark months I needed to help charging from the mains power, but now the same radios can be supplied with solar power again. It's likely that I will add more panels and an extra charge controller or two to the 12V system.

The total capacity of the 12V system is about 2.5kWh, and I have used it with my power hungry IC-9700 and a bit of other radios. It's possible that I will add a bigger 12V battery later, for a capacity of about 6kWh.

Enter the 24V system. The plan is to add the capacity, so I will have a total of about 7 (or 9) kWh at the radios, using a simple DC/DC charger from 24V to 14V, with constant voltage/current setting and some switching control.

Some more solar panels need be added to th 24V system. I have some already, but I need to get them mounted.

I have found some reasonably priced 450W panels, and I will likely add a few of those to the system.

I have a small and a larger power station(s) that will likely be added to the system. Also, I have some LiFePO4 cells, so I can make a 12V, 24V and possibly a 48V system for the workshop upstairs.

A tiny system for lights and audio in the bedroom is also under construction. Yes, there are many smaller and a few larger projects to build here, along with the radio experiments.

Tidying and Birthday Present.

 As the house is a total mess, a massive task of tidying has been started. It will likely last the whole year, or longer. 

The first task was getting down to the surface of the work desk, test bench.

I found most of the test bench surface ;).

Then I had my birthday recently, and I decided to get myself a present.

I have started doing a bit of microwave activity, and I got myself a TinySA a while ago. This measures up to about 6GHz and has a generator for the same frequency range.

It looks like the generator can show harmonic output well over the 10GHz range. Interesting.

So I decided that I should be able to check filters and amplifiers up to the 6GHz range, and purchased the corresponding NanoVNA, got it calibrated with the calibration set that came with the VNA. 

I have created a few presets, and saved them into the VNA:

350 - 550MHz

2 - 3 GHz and 

5 - 6GHz. 

There is space fro a few more, so I will likely add a range for the 3.4GHz band, the 1296MHz band and maybe one other.

The initial test today showed pretty realistic results, so I consider it a success.

Now I can do a bit of experimentation again. There is a plethora of small and big projects for all frequencies, from 472kHz up to 10GHz, at least. The experimentation may be slow, but it's possible.

Small Transceivers and Low Power.

I now have a rather good collection of small, low power transceivers (and receivers)

Some are low cost Chinese builds, some are small kits assembled by me over time.

Some years ago I purchased some "single frequency" (crystal controlled) transceivers (from Ukraine) tuned to the old frequencies used for the JT65 mode. When FT8 took over, the use of JT65 ceased, because the over all efficiency of FT8 is much better, especially because the transmit sequence is 4 times faster, compensating for the lower sensitivity. and the frequency was moved 2kHz up. 

Usually the crystal frequencies can be tuned down fairly easily, tuning upwards is more limited, so I don't know if I can tune the local oscillator (yes, those are superhet transceivers). If I can, I will try that and use them for FT8.

This would make for a very nice, low power (1W) single frequency transceiver on the 40, 20 or 15m bands. Yes I have those three.

Then there are some simple single frequency kits, (Pixie, Rockmite, and others).

I do have some crystals for the 40, 30 and 20m bands for reception of FT8 and WSPR/QRSS frequencies, and I might use those for monitoring those frequencies.

All this is part of an ongoing (open) challenge of making QSOs on as many bands as possible with my own equipment, and expand this with using home built equipment, too.

Until now I have made QSOs with my own erquipment on all available (in Denmark) bands from 160m to 13cm The equipment can do 6cm and 3cm, too, but no contacts done yet.

Contacts with home made equipment has been done on 80, 40, 30 and 20m on HF, and 2m on VHF.

When I use the expression "home made" I include modified equipment intended for non amateur use, and partly home made equipment, like using a home made 2m transverter with my HF transceiver.

Somewhere I have a Pluto SDR "transceiver" that can be used for all bands from 70MHz to 6GHz, albeit with extremely low power, so that one is a candidate for home made equipment on 70, 144, 432, 1296, 2400, 3400 and 5760MHz, with added front ends for the different bands.

I wish I had more time to do all those experiments. (Don't we all?)

1296 Tropo.

 I am reorganising my station, so the activity level is not so high.

Yesterday, however, 1296MHz was open up to a few hundred km.

I didn't make QSOs, but with my omnidirectional vertical monoband antenna I could hear 9 beacons during the day and evening:

OZ7IGY (of course, it's local at 26km, and always audible) - Everyting else is over about 200km

SR1KOL at about 270km

OZ1UHF at 222km

DB0XY at 438km

SK6MHJ at 229km

SK6UHG at 261km

SK1UHG at 416km

LB2SHF at 369km

LA3SHF at 372km

I am pretty sure I would have heard more beacons with a horizontal antenna, but this tells me that propagation was very good.

Yes, a horizontal antenna system is in the planning, probably for spring next year.

NAC on 1296MHz.

Yesterday I was up at the local hill with the '905 to operate a bit in the Nordic Activity Contest.

This time I brought a bit more equipment, apart from the 23cm yagi antenna:

- a tiny 3 band FM handheld, the Standard C710

- a 2400MHz long yagi.

Among a few contacts with SSB on the '905 and the 12 element yagi, with the local OZ4HZ, after the 1296MHz QSO we tested the 2400MHz band.

On 2400.500 we worked a nice QSO on FM with S9 signals noth ways. Now, with the correct polarization and operating from the hilltop, that was a massive improvement from the first test.

The test with the handheld radio was actually quite a lot of fun.

The radio operates a maximum of about 300mW on 1296, and some of the strations in the Copenhagen area had excellent signals. This radio comes with a tiny 10cm long "rubber duck" antenna, so I was a bit in doubt about the range. The first QSO was with OZ1GIN, working with an indoor antenna 2 small yagis, and reported S9 signals from the radio at about 25km. Yes, he was running horizontal polarization, so it was simple to turn the hand(held) for that.

A bit later I tried with OZ4HZ, and again wee had S9 exchanges, and a less local station, SM7FMX, just over 40km away)  came in for another handheld QSO with good signals.

All worked well, and then I noticed that the radio was in low power mode, so all those FM QSOs were actually worked with a mere 100mW. Now, that is fun portable work on 1296MHz.

I will probably try going light-weight portable on the hill with the handheld and a somewhat larger antenna, so everything can be carried in the rucksack.

New Toy: Handheld "Micro" QRP Transceiver.

 Today I received a small (even for my hands) handheld transceiver. 

The price from Ali Express was not too high, about €130.

This rig is based on the uSDX transceiver, but built into a handheld type casing with a rechargeable 1100mAh Lithium battery. 

I consider this Chines radio as a bit of a toy, so if it won't work for my purpose, it's worth the price for experimentation.

No manual included, so I pushed the power button to see what happened. Lo! and behold ...  The thing switched on and showed 14.074 (yes, the FT8 frequency on 20m), ans sound in the speaker. At least it appears to be working. 

Now, how to switch off this thing???

The power-on switch now acted as a PTT switch, so no good. long push (PTT), double push ... nope!

Internet to the rescue (almost) I found that the volume control set to level "0" should switch it off. Not quite ... I needed to push the wheel, and then turn it off.

Okay, at least I would not deplete the battery capacity.

The TRX essentially does what the uSDX does, so I am interested in how it will work with digital modes, like FT8.

This little radio can receive from 500kHz (?) to 30MHz, and is capable og transmitting on all the HF amateur bands. However, the filters are adapted for the 10-15-20-40m bands, and if I want to use it on other (especially lower) bands, I will need external filters. So the first tests will be on those bands.

I need more testing. I have seen a test by OM0ET on YouTube, and that's why I wanted to try it out, as a fun experiment.

OM0ET also has a video describing some modifications that would make the transceiver more useful, so after an on-the-air test, I might try those mods.

QRO or Not QRO? That Is the Question.

Some years ago I got myself a used HF power amplifier for 1kW.

The ACOM 1000 is regarded as a solid amplifier that holds it promises from 160m to 6m. That is also my experience.

However, with quite short distances to neighbours' houses, I am not quite comfortable with using it.

In fact I used it briefly on 10m with about 400W out. That was when the solar activity was still quite low.

Then I used it on 50MHz, also with about 3-400W. Tha antenna that could endure that kind of power was removed, and for some years I have used the V-2000 for (2m, 70cm and) 6m. Under no circumstances would I use more than 100W with that one, especially with  FM or digital modes like FT8. The capacitors will not stand that, and will be transformed into carbonized components.

So today the ACOM 1000, which has been on the radio shelf for a few years witout being connected to the power outlet (or a transceiver), was taken down from the shelf. I am probably going to sell it and get some more UHF/SHF equipment.

I will not abandon HF completely, but focus more on VHF/UHF/SHF, going a bit back to my old interests.

Over 30 years ago I was working a lot on 2m, 70cm and 23cm with relatively low power and decent antennas, and over 40 years ago I was working crossband 50 or 70MHz to 28MHz, and had a lot of fun with that. Now I want to try the even higher frequencies, too. probably mostly portable from hilltops, but also with a (very modest) station at home.