New Toy. IC-9700.

I have been thinking of getting myself a VHF/UHF transceiver with a matching screen, like on the IC-7300 I already have for HF, 6m and 4m. 

I already have my older IC-910, running okay on 2m, 70cm and 23cm. It a good transceiver, especially after I replaced the standard reference oscillator with a high stability one, and installed a 1200MHz module. It's perfect for general operation. It does multimode, including SSB and CW, but I have missed the possibility from my newer HF rigs, for having a spectrum display. But the '910 is an ageing transceiver, and who knows when it might break down?

For 2m and 70cm, this can be achieved with the IC-705, a bery nice l0ow power transceiver with a neat spectrum display, like the one in the '7300. However, I have plans for trying 1296MHz again. I did that some decades ago, and found it good fun.

Enter the IC-9700. This transceiver This comes with all three bands included as standard, 144MHz, 430MHz and 1296MHz, and it does have the spectrum display, much like the one in the '7300.

I found a used one recently, with 6 months remaining warranty a few days ago, and decided to make the jump.

The box arrived yesterday, and after a bit of work installing it, it is now running on 144MHz with a Big Wheel antenna, and on 70cm FM using the 70cm part of my V-2000 antenna (via a triplexer) I still need to test it on 1296MHz, but my antenna for this band is still mounted very low, and it's difficult to make even local contacts. Yes, there is low activity on that band, but I hope to get more stations running, as a lot of fellow hams have '9700s with an unused 1296MHz band.

So next year I should try to make the update of my antenna system, for various reasons I did not get that done this year.

PA Transistors Found at the Rally.

 There was one more thing I found at the rally.

1.9GHz PA transistors capable of about 60W linear output, apparently LDMOS. 

I found a set of 14 pieces packed in an antistatic container.

The transistors come from CREE Microwaves and are marked LGA19060-171. Does this relate to 1.9GHz and 60W output? 

I do not know if they are internally matched. If they are not they could be interesting for a number of PA constructions for different frequency ranges.

My main interest will be to see if I can get those running on 1296MHz. Two of those should be capable of generating 100W. If they have internal matching an external impedance matching circuit should be made.

Since they came at a low price I can do some experimentation without being afraid of destroying a transistor, and with 14 of them I should be able to make a workable amplifier with them.

I was recommended contacting a local amateur, as he may have some tips for overcoming the possible internal matching, so I can use the transistors well outside the design frequency.

As there most likely will be a lot of experimentation, this will be a future project, as there are already so many ones already to be made.

If anyone knows more about these transistors, please let me know.

Mini project #4B: Small 70cm Flexa Yagi, and Some Thoughts on the Higher Frequencies.

When I purchased the small Flexa Yagi antennas some time ago it was the intention to make a compact, not too visible antenna system for 2m/70cm/23cm SSB/CW etc operation. At the time I had chemo therapy, so everything went too slowly, and the project almost died.

This project has now been resurrected, and I got the 3 antennas assembled. 

- 4 element yagi for 144MHz

- 11 element yagi for 432MHz (strictly speaking 8 elements, as there are 3 reflectors making a reflector plane).

- 16 element yagi for 1296MHz

The Flexa antennas have very thin steel elements (and a not too heavy boom), reducing the visual impact of the antennas, as I wanted

All these antennas are made for mounting in front of the mast, i.e. "behind" the reflector, so the mast will not interfere with the function of the antenna by blocking part of the elements, especially on the higher frequencies.

Having all antennas front mounted will create an imbalance of the load on the rotator, so I am thinking of making a compromise here: Mounting the largest antenna (the 4 el. for 2m) on one side of the mast, then mount the 70 and 23cm antenna in the opposite direction. This will make the operation a bit more cumbersome, but I think it can be done.

I may add a Moxon Rectangle for 4 and 6m to the system. This is a rather small antenna and will not add significantly to the visual impact.

Further, some small antennas for the 2400MHz and 10GHz band are expected to be added. No parabolic dish there, just some tiny yagi or patch antenna for 2400 and a small horn antenna with a transverter for 10GHz. This is for later, but initially a LNB (frequency stabilized), maybe with a small horn extension will be mounted for 10GHz monitoring purposes.

I will need to mount this on a rotator. No need for a heavy duty one, so I am looking into options.

I intend to mount the system on top of an old apple tree where I have some antennas already.

For SSB/CW (DX) work I have had a clover leaf ("Big Wheel") antenna mounted right on the top of the tree, essentially invisible, and it has provided some DX on 2m.

What kind of performance can I expect from this system.

On 2m, the stated gain of the 4 el. antenna is 7.6dBd. This may be exaggerated, but compared to the old clover leaf antenna I expect to mount the 4 el. 2-3m higher and less obstructed, so I would expect a performance improvement of approximately 10dB over the clover leaf antenna. With a good preamp at the antenna, and also an added PA in the shack I should have a solid performance boost, compared to the current system.

On 70cm, with a stated gain of 10.2dBd the system is a very modest, but some DX activity should be possible.

On 23cm, with a stated gain of 14.2dB (exaggerated?) I would expect some interesting occasional DX activity, especially if a preamp and a PA (25W?) is mounted near the antenna.

On 13cm this system will just be playing around , maybe with some interesting DX in the best directions I have, but I do not expect much there. 

On 3cm  the system is very modest. I may be fortunate enough to make some DX under excellent tropo conditions, and possibly some rain scatter QSOs. 

For the higher (microwave) bands some hilltop operation is probably a much better option, but the capability of some modest home operation is good to have.

Beginning of the Sporadic E Season.

Monitoring FT8 signals on 10m has shown me two things:

1) F2 propagation is slowly starting after the deep solar minimum. I regularly detect signals form South America, a bit of the Middle East and a a few stations from Oceania, mainly Indonesian stations. I am looking forward to be able to work stations world wide with CW (and maybe SSB) on 10m, maybe even with QRP.

2) Most days I detect signals from all over Europe, mostly at distances of more than 1200km. Soon I will have to change the monitoring to 6m and maybe 4m. 

At the same time I am trying to reduce the visual impact of my antenna system as much as possible.

Last year I had separate vertical antennas for 6m, 4m and 10m. Not very good for low visual impact. This year I am planning to test an unusual antenna for multiband use: A 10MHz ground plane antenna. This will have a low impedance resonance on 30 (workable on 28MHz with a tuner), 50 and 70MHz, with some low angle radiation. What remains to be seen is whether this will work well for 6 and 4m, if it does I will keep that as a vertical for 4 bands. With a frequency multiplexer I should be able to use the antenna simultaneously for all 4 bands. I have a diplexer separating HF and VHF, so that is a start. But before I can do this I will have to dismantle my separate 4m vertical, and that is too difficult without assistance. I hope that the COVID restrictions will ease sufficiently for that to be possible, very soon, so I do not miss too much of the Es season.

There is more antenna maintenance needed, but this has a rather high priority.

I have some ideas for making a very modest rotatable antenna system for 6/4/2m and 70/23/13/3cm. For 3cm DX I know I will need something larger, but I have to start somewhere. More on this project later.