2024-05-29

IC-905 for Home Use?

I have only used the IC-905 for portable use.

It is not practical to use it for both fixed and portable. There will be too much going to the top of the mast/rotator mounting and dismounting the outdoor unit (ODU), also the weather proofig would have to be done every time. However, I am beginning to look into uses where the ODU is used indoors. The first thing that came to my mind was using it as the base transmitter for QO-100 uplink.

Until now I have used a 70cm transceiver with an indoor up-converter, the Chinese BU500 and an outdoor PA (WiFi booster). This has worked nicely, even if it occupied an HF/VHF/UHF transceiver for that.

As I am not using the IC-905 for anything else at home (yet), I set it up as a 2400MHz transmitter. One great advantage is that the '905 has a built-in GPS lock for the system, so I do know the frequency I am transmitting on.

A small experiment. today I set up the '905 with the ODU indoors on a shelf in the shack, and use it in place of the old system. A quick test showed that it works nicely. with the transceiver running about 600mW (out of 2W possible) to the old outdoor system.. Everything works nicely, though the SWR seen from the transmitter is on the high side. I tried to use a 3dB attenuator to reduce that, as I do not want to destroy the PA in the unit. It looks like I destroyed the outdoor PA. I have a spare, and a larger one from SG-Lab that just needs a heat sink, and it could be put to good use here.

With my old feed antenna for the dish, the signal is perfectly readable, so I am happy with the results so far.

The signal is not so loud, but I can work through the transponder CW and SSB.


2024-05-22

NAC 1296 May From a Hilltop.

Tuesday evening we had the 1296MHz segment of the Nordic Activity Contest.

I decided to go to a nearby hilltop at 80m ASL. It is in the same locator (JO65CP) as my home, so it's a short drive, and a walk of about 500m with a climb of about 40m at the steep part the slope is about 20 deg.

Due to the walk I only brought the basic gear fitting into a rucksack:

- the IC-905 control unit with the microphone and the RF unit, and of course interconnection cables

- a 12 element yagi with a few metres of cable

- 2 tripods, for the control unit and the antenna, fitting at the sides of the rucksack.

- a 12V 20Ah LiPO4 battery.

- a small log-periodic

- a paper logbook (computer is too bulky and adds weight)

This fills the rucksack up and is still fairly easy to carry on the back.

Additionally a very light weight support (without backrest), so I could sit a bit while operating.

The walk from the parking took me about 20-25 minutes, and the setting up another 10-15 minutes, so I was ready about 10 minutes before the test started. Time to test reception of the 2400MHz and 5760MHz. The test was done with the tiny log periodic PCB based antenna, and both beacons came in with good signals, even with the antenna less than half a meter above ground, and with some attenuation from trees.

This is a pretty good place to do some microwave activities, despite some bushes shading the signals in some directions.

Time to listen on 1296 before the test.

Beacons coming through: OZ7IGY (of course it is less than 25km away), OZ5SHF at another hill 155km away, OZ1UHF at 220km, SK6UHI at 261km, the DB0VC in Kiel at 185km, and finally LA1UHG at 394km. Not bad for a small 12 element yagi antenna and a non modified radio. The setup is working.

Tarting the test I was listening to OZ7TA at about 40km, also at about 80m ASL. Not surprising the signal was booming in, as there is line-of-sight. He had some trouble with his setup, so I missed the QSO.

A total of 9 QSOs were made, not too bad for a first outing. The best distances were OZ3Z at 157km and SM6CEN at 195km.

OZ1LXL at about 40km was shocked, my signal was the strongest he had heard on 1296, and we had a comfortable QSO using FM.

Lessons learned:

Lesson #1: I need to bring a CW key(er). Several stations were calling CQ in CW, and I missed them If I just wanted to call and make a standard QSO I could have done it with pre-programmed texts in the built-in keyer, but I had not done that. If I wanted to male fully random QSOs, calling CQ myself, I could do the CQs with the pre-programmed texts, but I still need the keyer to send the call of the caller. Good lesson: make some pre-programmed texts, and bring a simple key(er) for CW.

Lesson #2: I need to bring a handheld for 2m and 70cm. Some locals would like to coordinate, and know that I was on 1296 from a hilltop.

Lesson #3: I should switch the tripods. The antenna could only be raised to less than 1.5m above ground, and it should go a bit higher.

Lesson #4: I could use a smaller battery. the current battery is quite bulky, filling up a good part of the rucksack, and could go for many hours (more than I needed for this operation). This might give some space for the 10GHz module for another outing with the IC-905.

I did have a good day (evening) at the first operation from the local hilltop, and I think I will try it again, with improvements of the setup.

If you have any other ideas for improving the "real portable" outing, please feel free to suggest them in comments.

Edit:

I found that it is possible to use some of the microphone buttons as a keyer paddle. Good to know another time. I think I could have made a few more QSOs that way. Yes, learning is a good part of this.


2024-05-02

Aurora Heard on 2m.

 Today the arrival of a double CME from the sun resulted in aurora on 2m.

I heard several solid signals, but due to my poor antenna, a "Big Wheel" (cloverleaf) antenna, I did not make any contacts.

And one of my favourite radio propagation sites SolarHam is back. I had solarham.net in my links, and it stopped working, so tried solarham.com today, and there it was.

K- index went high

First time in a long while I have heard such strong aurora on 2m in a long time.

The opening lasted about an hour, and the interplanetary magnetic field  (Bz component) went almost neutral, and then South again, so there may be an update later today.

Update 2100Z:

The K-index higher again, but I was not hearing more aurora with my small antenna.