GHz on Gun (G~SP-013)

Activation Reports
1

I have not done much SOTA, or indeed much hillwalking since damaging my knee while doing some roof repairs (torn Meniscus, LCL and ACL) back in August 2024.

On Sunday (28/09) there was a UK wide GHz contest, so I thought I would go out and try my newly acquired 5.7GHz (6cm) transverter. If I could combine this with an easy SOTA summit, all the better.

G/SP-013 Gun (IO83xd) was chosen because

A) It is my 4th closest summit

B) Not activated by me this year

C) Easy walk to summit

D) Guaranteed parking

The evening before : in addition to the usual charging of batteries and checking all kit (+spares), I prepared a sheet of stations probably taking part, including location, and most important, bearing from the summit.

The event runs from 0700 to 1900 local time but most of the activity is in the middle of these times. (I don’t think there are enough stations to keep you occupied for that long).

I set off at 08:30 for the 60 minute drive to the parking spot. I quickly unloaded the car and walked up to the summit, carrying a rucksack, a large shopping bag, a mast and tripod. The weather was dry and calm, but a little overcast.

First job at the summit is to set up the mast with the 10GHz transverter and mast. Attach the battery and FT-817 that I was using as the IF. Switch on and leave to warm up while I assemble the 5.7GHz gear. Next, fire up the laptop and log in to ON4KST chat to liaise with other operators. Wait, the phone signal is rubbish and my connection keeps dropping out. The solution is to force the phone to use 3G and then strap it half-way up the mast with cable ties.

Now on to KST and arrange my first 10 GHz contact. G4ASR (IO81mx)- a regular and well known microwaver, who I know I can contact (*this is important). Sked arranged, compass bearing set and antenna pointed in the right direction.

10:20 and TX 5/8 - RX 5/4 reports are exchanged, along with some pleasantries. My first contact is in the log. (*shows my radio is working AND it is reading +7kHz).

Next I get a message from G1EHF/P on (IO91gi) to try on 5.7GHz. I am skeptical this will work as this transverter is quite new to me, and I have not worked any great distance yet. We agree a QRG, set the bearing and point the antenna. His signal is there almost immediately, but we both have to tweak our antenna a little before we make the QSO.

He then asks if I could try G4SJH/P on the same hill, but on 10GHz. This one was a little harder, but eventually we made the contact.

Great, just over 200km with the added bonus of a S2S as they were on G/SE-001 Walbury Hill. (confirmed by email that they were at the trig point and running on batteries).

I spent the next 4 hours trying to get contacts. Some were easy, but many were difficult and required many, many repeats (+10 minutes) of report & serial no.

Last QSO was 14:22 at which point a few drops of rain was felt, so time to pack away and head off home.

In all I made 7 contacts on each band, with a total of 9 different calls.

G~SP-013 Gun Moor
G~SP-013 Gun Moor1920×1152 136 KB

Cheers…………Stuart

25 Likes
2

Hey Stuart, I don’t know much about microwave operations, I would like to know a bit more about the kit you used during the activation, can you briefly describe the radios/transverters/antennas?

Thanks.

1 Like
3

I try to keep my equipment simple to set up and operate. On this activation I used the following…..

5.7 GHz transverter from SG-Lab.com and a panel antenna for the correct frequency. The antenna is sold as WiFi Boost antenna and has 23 dBi gain. The battery and transverter are mounted on the back of the antenna. Transverter is 3W output.

10GHz transverter is an old Kuhne/DB6NT model (MKU 10 G3) which are no longer available. In the box on the mast is the transverter, 2W amplifier, a TX/RX sequencer and antenna relay.

Both transverters are driven by FT-817 radios. 144MHz is required for 10GHz and 432MHz required for 5.7GHz. I chose to use 2 radios this time, but I could use just 1 and switch band (144 on front antenna socket and 432 on rear antenna socket).

3 reasons I chose these antennas instead of a dish. 1. easy to carry to a summit. 2. less likely to get damaged if I drop it or the wind blows the tripod/mast over. 3. they have a much wider beam width than a dish, meaning you don’t need to be pointing so accurate to get the initial signal.

If you want to try microwaves, i would recommend the lower bands first. (1.2GHz or 2.3GHz) Transverters from SG-Lab are small and relatively cheap. You need to email for price and availability as not all transverters and amplifiers are on the web site.

If you wanted to try 10GHz then I would currently recommend the kit from OK1FPC which again, you will have to email for a price.

Thank you for the interest, maybe one day I will try HF.

Stuart - G1ZAR

3 Likes
4

Stuart, I agree with everything said, except LG Labs gear is anything but cheap. It’s more than worth the price. Bang for bucks. :wink:

Ahoi

Pom

5

In the old days I guess we’d have used a Gun diode

I’ll get my coat …..

Rick

3 Likes
6

The great thing about the lower uWave bands is you can get lots of antenna gain simply. No need for complex Yagi where the mechanical tolerance is quite high. Patches and bowties are simple to homebrew.

I have made double-quad / bowtie antennas for 23 and 13 cm. I also made a double-double quad. Essential materials being PCB material and some 2mm diameter brass tubing, a bit of UT-141 cable etc. and a suitable connector.

I’ve been playing with a commercial Wifi outdoor antenna really for 2400MHz not 2320MHz. It was made on a backing plate of 20swg mild steel so weighed a ton. I’ve just done my first drilling job using the Dremel drill stand I bought the other month and have swapped the mild steel backing plate and earth plane of the antenna for some single-sided 1.5mm FR4 PCB. SWR on the VNA was 1.4 at 2320 and it’s about 1.2 at 2400. The antenna is 4x patch (2 in series in parallel with 2 in series for 50Ohm) and claims 15dBi. It’s better by far than my double-double which is a bit off since I dropped it :frowning:

The antenna is now 450g lighter. Wow! That’s the equivalent of 11 KitKats :-1:

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