Today I’ve been working on the Cavity duplex filter for the new DMR-repeater. The exact frequency is yet unknown but I assume it will be 438.3125 MHz for the output and 430.7125 MHz for the input, which makes a -7.6 MHz shift.
I’m the lucky owner of a Rigol DSA815 Spectrum Analyzer (9 kHz – 1,5 GHz) with tracking generator onboard so the mandatory tools are available.
I’m busy preparing a new DMR-repeater. The exact location is unknown but having a look at white spots in the coverage maps from the current repeaters most-likely it will be somewhere in the Northern part of the Netherlands.
The repeater is the Hytera RD985 so it will join the HYT-network. Currently there are 3 options for locations that are being investigated:
Today Lucas (PD0LVS) and Ron (PA4RVS) drove to Hoogland to view my new house and helped me out to put the loop back on the tripod in the garden. The hours before I was busy unpacking my equipment to build a new shack. All the basics are there and the big question was: How was the man-made noise around the house?
Though I do hear some PLT noise, it’s nothing compared to the S9+10dB I got for free on the 40-meter band in my old QTH. All bands seem to be quite clean with almost no noise. Hooray!
After D-star there is DMR. Not that I’ve used D-star much but just want to give new techniques a try. Yesterday I’ve ordered a Hytera MD785G. This is a mobile UHF-transceiver for both analogue FM and DMR. Ideal as a second set for the local repeaters since the 2nd VFO of my Icom IC-9100 is RX-only.
The MD785G has 25 Watts of output which should be more than enough to work repeaters in a 20 mile radius. The nearest (temporarily) repeater is only 500 meters from my home, the first production repeater about 15 miles.
We will move over to a new house next month, so time to clean up the shack. New QTH will be Hoogland (Amersfoort) as of half October. All antennas are indoor for the next two weeks, including HF via the loop.
After weeks (months) I finally found some time to test the Wimo / I3VHF / Ciro Mazzoni loop-antenna for the 40 till 10-meter bands. First QSO was with UA9MMC in JT65 on 20-meters, resulting in -13dB reports.
It’s more than 15 years back since I did exam for the Novice license. Today I took the shot to go for the Full/HAREC exam. Totally unprepared I passed the exam with 11 wrong answers, where 15 is allowed. So I passed. Finally access to WARC and the 6 meter band.
The RSGB IOTA contest for 2013 is over. This year we activated the island of Texel (EU-038) as PG13IOTA. It’s very nice to operate in an environment without man-made noise. In particular on the 40-meters band, where the average noise level from my home is S9+, which makes local QSO’s even hard to follow.
Nice thing about this years’ activation was the help we had from SWL’s Lucas, Roald and Ron. Two of them are going to do there ham-radio exam in September this year. They should be very motivated after the weekend where they helped operating our station.
Today I’ve mounted the new tripod and portable aluminium mast on the roof. The HF-antenne is about 6 meters higher now. Total height will be around 10 meters from streetlevel. The tripod is fixed on a planter with enough weight so it won’t tilt over. And it it becomes stormy here, 5 miles from the sea, I’ll just lower it.
Next project will be unpacking and testing the baby-loop antenna from Wimo.
Forget my post about the MFJ-1788 loop. One day after ordering Wimo mailed me that the unit was not in stock and the re-supply was on the 21st of June or later. They offered a full-refund. I mailed back, asking if they could do anything with the price of the Baby loop. The aswer was no but the salesman mentioned that they had an upcoming discount starting on the 16th of June and I had to wait for that date. Not knowing what the discount was, I decided to keep the MFJ-1788 order open.
This week I had a look at there website and noticed they offered a 10% discount on all items plus free shipping for goods up to 200cm in lenght. Thats where I decided to cancel the MFJ-1788 loop and order a Baby loop. Yes, it’s (way) more expensive but you’ll get the 6,6-29,8 Mhz coverage while the MFJ stops at 21 Mhz. Thus the 12 and 10-meter bands are included.
Bigger plus it the automatic tuner. Just enter the frequency in the keypad and tuning is done in seconds. Then there is the building construction that looks way more robust than the MFJ. So you do get value for you money.
The Baby loop is produced by Ciro Mazzoni in Italy. The diameter is 1 meter instead of the 90cm MFJ offers. Besides that, the Baby Loops’ tube has 50mm thickness that should give a beter radiation pattern, especially on the 40 meter band. Not even mentioning the maximum power is 250 Watts instead of 100, tough I only work QRP with 5 Watts or less.
Now waiting till my order is confirmed, the loop on stock and shipped towards me. I guess that will take another two weeks. When it’s in, the results will be posted.
I’ve ordered a Baofeng UV-5R to do some experiments using a Raspberry Pi to encode an audio stream. Today I ran against some issues programming the device. Using a Wouxun cable which has the same pin lay-out as the Baofeng (Kenwood compatible) and installing the latest driver the problem was that when reading out the radio this process stopped after xx blocks of data. Nothing special in the error so I start Googling on read from radio + Baofeng and it was likely the driver version from the USB2Serial adapter was to new. Downgrading this to v126.96.36.199 was the solution, found on this website.
I should stop ordering stuff. Really. The antennes I’ve ordered a month ago aren’t in yet (shame on you vpa-systems.pl) but today I’ve ordered an MFJ-1788 loop-antenna for the 40-15 meters band. Let’s see how this works, in particular on 40-meter, where my day-to-day QRM is always S9 till S9+10, thus quite unworkable.
Now wait a week or so till Wimo in Germany will deliver. I hope they have the antenna on stock, because a local supplier in the Netherlands didn’t.
Update 23-06: Mail from Wimo, not on stock. Will have to wait one month. Suppliers, really: if you don’t have stock, report this on your website!
This week I’ve ordered some new antennas. A dual-band Moxon antenna for 28 Mhz with a 2-element antenna for 50 Mhz. A simple antenna to make, but I’m just to lazy for that. besides that, I’d rather spend my free time on something else than cutting aluminium. I simply can’t stand it and get rash from the iron powder. So I’ll just stick on building my own HF-antenna’s.
Dual-band antenna. Moxon for 28 Mhz and 2-element for 50 Mhz. Boom=1,5m, total width=4m.
The other antenna I’ve ordered is a dual-band yagi with 5 elements on VHF and 8 on UHF. The boom-length is 1,50 meters and the design is from DK7ZB. The gain should be around 11 dBi on both bands and it has a single coax feed. Let’s see if we can catch some BHF-tropo or satellites with this one.