I have been thinking about using a suitable VHF / UHF preamp for a while now. It would be nice to have a preamp that I could use during the Tuesday evening activity contests as well as having one to use for receiving JT65b signals with EME as part of my Moonbounce project. The PGA103+ is a low noise, high dynamic range preamp which will operate from 50Mhz up to around 3Ghz. Being wide band brings it’s problems, but it is very versatile and sounds like just what I need at the moment. I decided to buy a ready made preamp board from G4DDK, the components are all surface mounted and I have not yet attempted to make anything like this with my limited soldering skills! The G4DDK board is tiny and my first task was to make a suitable case with N type sockets. The G4DDK board has fittings for SMA sockets, but I really needed either BNC or N type to connect the coax.
The housing is built from double sided copper clad board, I have had a lot of experience in the past using this, many of my earlier projects used DS board. It is easy to cut, drill and solder into cases. In the photo you can see the N type sockets fitted and also the G4DDK board.
My first attempt caused some problems, the preamp board worked, but was rather unstable, a rethink was required…
Adding a screen between input and output and making sure that the earth side of the preamp board was thoroughly earthed to the case cured the problem!
Now I just need a lid out of DS board to complete the project.
Testing the preamp on 144Mhz seemed to work fine, bringing GB3VHF from just below the noise to a reasonable level above the noise. I now need to test on 432Mhz and 1296Mhz to see how it performs.
Call me crazy if you like, but I have become hooked on this Moonbounce using JT65b. I am sucessfully making normal contacts on HF with JT65, this is such an addictive mode of operation, quite theraputic!
My goal now is to try to receive a signal using EME, something that up to now has been imposible with other modes for me. So I have set about building an antenna system for 144Mhz and 432Mhz with a vision of actually having a QSO through EME with the minimal equipment. The first part of my project was to adapt a 144Mhz yagi (which I already have) to fit my Celestron computerised telescope mount. I have been using the computerised mount for years now to take images of the Moon, planets and other deep sky objects. If I can set up the computerised mount with the telescope and then replace the telescope with a yagi antenna the mount will then track the Moon in real time. My next task was to make a ‘wedge’ to fit the mount out of wood and a plastic tube screwed to it so that the yagi can be placed inside. Using the tube also allows for changing the polarity of the yagi anytime I want to. For this I used some plastic waste pipe from B&Q along with some modified mounts. This worked fine, but I needed to overcome another problem, the weight of the yagi needed a counterbalance on the other end of the tube to keep it all stable. I solved this problem by using an old transformer!
Four element yagi screwed to a broom handle and pushed into the plastic tube for the computerised telescope mount. At the bottom is the old transformer acting as a counterbalance to keep it all stable.
My next task is to build a 432Mhz yagi and try out the 144Mhz yagi to see if I can receive anything on JT65b…..fingers crossed!
Like Slade said back in the 70’s “Ma…mama we’re all crazy now” but this is not as crazy as it sounds having read the latest stuff about EME and JT65b.
I have read about the lesser known digital modes like JT65, but have had trouble getting my head around how it works. I think it was originally designed for Moonbounce (EME) contacts. Recently at the exhibition station at Smithills Hall I spent some time with Chris G4HYG who was operating a JT65 station and working lots of stations. He took some time explaining to me how it works and this inspired me to have a go myself. Chris used WSJT-XT, so I downloaded it on my computer and set about setting everything up. WSJT-X has quite a simple interface, but it took me quite a while to get the setting right. At first I could not get the PTT to operate correctly, giving me ‘Hamlib errors’ I am using the correct CAT settings for my Yaesu FT857D and am using Ham Radio Deluxe. Seemed to be some contention with the PTT ports?
After spending a long time messing with it I put a post on the Amateur Radio Group on Facebook and got some really helpful replies:
I have been trying out WSJT-X with JT65. The receive works and decodes great, but when I transmit the PTT operates then immediately drops out giving an error – Hamlib error – IO error while opening connection to rig.
I am using a Yaesu FT857D with CAT interface (Port 9) and PTT interface (Port 6) These work fine with HRD other programs for PSK31 and SSTV.
As far as I can see my settings are set correctly in WSJT-X.
Anyone got any ideas?
I was getting that error because I had FT-817 commander running at the same time as WSJT-X. They were fighting for the same COM port. Try closing HRD and doing all the CAT stuff from WSJT-X.
HRD and WSJT-X work perfectly fine together first start hrd with the 857 then open WSJT-X in FILE/ settings click the radio tab and choose Ham radio deluxe from the drop down list et voila all cat commands for WSJT-X are carried out by HRD now if you also start dm780 in hrd you can use that to log wsjt-x contacts too… hope this helps been running them this way for 4 years www.Lbar.uk P.S. I’m a Windows 10 user and have been for 2 years….
My problem was solved, I had set WSJT-X to Yaesu FT857 instead of Ham Radio Deluxe, changing this solved all the problems! Now I am ready to try working some stations…but along came another problem…the computer clock. You need to have a very accurate clock, Windows clock is just not accurate enough, so I changed the time settings to time.nist.gov this works fine with Windows 10 on my computer.
Now we can work some stations…well almost…JT65 and WSJT is a frustrating mode to operate. I can monitor stations coming in, but when you call a station or call CQ you have to alert, waiting a minute between receiving and transmitting and reading the stations decoded, you have only a few seconds to press the buttons to set up your QSO. I got quite frustrated at first, but now I am getting used to it!
Tonight I finally managed some JT65 contacts on 40m!
This was my first complete QSO with SQ9ZAX
PSK Reporter screen print following the contact.
The amazing thing about this mode is that I was also heard across Europe and across the Atlantic by looking at PSK Reporter. I was only running 10 watts into a 1/2 size G5RV antenna.
Now I need to practice a bit more using the software and working more stations on other bands. Maybe I will try Moonbounce on 144Mhz using JT65 when I get more confident.
At last I have managed to erect my new colinear antenna. I bought the dual band collinear form Mirfield Electronics at the NARSA Rally at Blackpool earlier this year along with mini 8 coax. My biggest problem is where to mount the antenna, I don’t want it on the front of the house because it is screened by the house next door. I want to be as clear as possible in all directions, I considered putting it on the chimney, but that would mean hiring someone to put it up there!
So during the hot weather I sat in the garden and pondered for a place to put it without too much hassle….
When I started to put the colinear together I found that there was a problem. The u bolts supplied with the mounting were too big for the 1.25 inch diameter aluminium pole, it looked like it was meant for 2 inch or bigger. In the end I had to solve the problem by packing the u bolts with some wooden blocks. The colinear itself is very well made and quite heavy, but I think the choice of mount needs looking at again.
Once the colinear was complete I then tried out the antenna with my Yaesu FT857D. I could compare the colinear with my present discone antenna (which works well on 144Mhz) and see what the difference would be. Listening on 144Mhz I immediately noticed stations I could hear that are non-existant with the discone. Comparing stronger stations showed that the colinear was significantly better and tuning around I could hear weak stations from quite long distances. With 432Mhz activity is quiet most of the time, but I was able to access and listen to the local repeaters which come it very strong, much stronger than I receive using the discone. On transmit the SWR was almost 1:1 on both 144Mhz and 432Mhz.
Quite impressed with this small colinear for the price!
A lovely hot day for erecting antennas!
The new colinear mounted next to the discone.
My first visit to the new Modern Radio today, so I took a couple of photos of Diana, Susanne and the new shop 🙂
The new premises is on Gladstone Rd, Farnworth,next to Apollo Motors and opposite Hawker Siddeley Social Club. You can park on the social club car park.
Been going to Modern Radio since I was 12 years old, that’s 50 years!
Celebrating 50 years of Pirate Radio, The Radio Caroline ship MV Ross Revenge came on the air again for a special event station GB5RC!
I managed to work the station on 80m late on the Saturday night despite the pile up of stations waiting to work them. I used my Yaesu FT101E transceiver, very fitting as the Ross Revenge was the ship used by Radio Caroline back in the 1980’s.
Still got the t-shirt!
Here is GB5RC on the air!
Had a really enjoyable day with the Bolton Wireless Club Special Event Station GB3SHM. It was great to meet many amateurs that I have spoken to regularly, but never met them. Nice to put faces to callsigns. Today reminded of the old days with the Bolton and District Amateur Radio Society back in the 1970’s when we held special event stations and field days. The Bolton Wireless Club uses the old G8WY callsign that I used to use back in the 1970’s.
A nice set up complete with barbeque!
Mick M0ICK and Richard G4HGI operating 10 metres.
Jack G8HIK operating digital audio modes.
Chris G4HYG working JT65A on 20 metres.
Nice video made by Jack G8HIK…