I’m Randy, a 38-year old ham living in Amersfoort, which is located about 25 miles east from Amsterdam. Licensed since aged 17 in 1997 and active on all bands from 10 meters up till 3cm tough VHF, UHF and SHF are prefered in (SSB) voice, ATV, CW and weak-signal/DIGI modes.

On the day to day job I work as Technical Consultant specified in Infrastructure and Linux solutions. Also doing some hands-on support stuff for repeater group PI2NOS and PI3UTR and PA6ATV (Hobbyscoop)  and trying to promote HAMNET and DMR-activities with a group of ham’s throughout the country.

New HAMNET link

Last weeks I’ve changed the HAMNET set-up. The radio is switched from Ubiquiti PBE M5-400 to Mikrotik using a 60 cm dish. The s/n ratio is now 50 dB(!) from my home to PI1UTR in the Gerbrandy tower, 31 km away. Furthermore I’ve switched to BGP-based routing with the fiber internet connection as back-up.

Storm :-(

Last week, storm hit the Netherlands with speeds up till 128 km/h. My temporary mast went down. A new base is ready to be mounted. This time with more counterpose and guy wires. The Moxon for 50 and 70 MHz needs some new aluminium. Besides that (and the bent platform) no damage to the roof. 

Buying 23cm transceivers in Japan

Last week I’ve received a shipment with several 23cm capable transceivers from Japan. One was the Kenwood TM-541 and two others were Kenwood TM-833’s. The 833’s are quite unknown since there are only brought to the Japanese market. basically it’s the more familiar dual-band 733 but now with the bands 70cm/23cm.

The first 833s (10 Watts) received was a plain transceiver (no cable, clamp or microphone) and was in excellent condition.  Clean and keen! It even had the LED display modification.
The second 833 had issues. The transceiver worked on both 70cm as well on 23cm, but the receiver on 23cm was quite deaf. I was missing about 20 dB of signal. Since I’ve bought two it was easy to compare. The pre-amp fet died. The next problem was to find out what fet was used, but one email to repairmen Leo was answered within minutes helping me out. I’ve ordered a new one in the UK for 6 euros and hope to receive it within a week or so.
The TM-541 looked dead when testing. The rotary encoder is borked. When hooked up on calibrated and reference synct testing equipment at the radio club we found out that the frequency was 22 kHz off. Trimming the VCO solved this issue in minutes. Now I have to find an hour of time to carefully remove the display which helds the rotary encoder to clean and lubricate it.

The 'UN' FET, which is a 3SK274. Thanks, Leo from radioamateurshop.nl.

The ‘UN’ FET, which is a 3SK274. Thanks, Leo from radioamateurshop.nl.

Importing transceivers from Japan:

  • Japan has 435.000 licensed ham radio operators. It’s a big second hand market! Japanese transceivers even have a function to find a free channel in urban area’s like Tokio. To find free space, Japanese operators go up in frequency. So there are many UHF-radios vor 70cm and 23cm.
  • Japan has S-version transceivers for Phone class licensees. These have limited power. For instance the IC-7300S. The amplifier module differs from the normal version. There is no software modification to upgrade to a full transceiver.
  • Most transceiver displays use modified LEDs instead of small bulbs to light things up. This may look weard, but occurs that the liquid crystals in the display dry out.
  • Keep in mind, repeater shifts are 5 MHz on 70cm and 20 MHz on 23cm. Only if the rig supports ‘odd frequency memory’, they are usable in the EU; For the TM-833, use the TM-733 manual since this one is quite well available online. The 833 manual is only available in Japanese.
  • The default frequency steps in Japan (and the US) are 20 kHz, while in Europe it’s common to use 12,5 KHz stepping. Unless your transceiver is 25+ years old, it should support 12,5 Kc steps.
  • Most transceivers come without microphone or cable. Be sure to double-check the photos and the (Google translated) description in the text.
  • Shipping from Japan will cost you about 50 euro and will take a week. Keep in mind that packages will be inspected by customs. PostNL will charge 17 euro for this ‘service’. If the value is more then 22 euro – and this includes shipping – VAT should be paid (+21%). If the value is over 150 euro, import (4%) tax should be paid on top of the PostNL and VAT fee.
  • A good place to buy is the Yahoo affiliated Buyee.jp. Select Auction and search for ‘1200 MHz’. It works just like eBay. But, when winning an action, choose the ‘Standard plan‘ for shipping from the seller towards the BuyEE facility. This will cost less than 10 euro in total. This parts differs from eBay since packages will be send to the BuyEE depot first.
  • When the package arrived at the BuyEE facility, they will store it up to 30 days for free. You can choose how to send it towards Europe. By boat is the cheapest solution but will take a minimum of 60 days. It’s also possible to consolidate several packages into one and there are options to use extra packaging since Post treats your package like a football.

23cm receiver PI6NOS

I’ve build an extra 23cm receiver for the regional 23cm repeater system PI6NOS in Hilversum. Building was quite straightforward. Just take a Raspberry Pi, an RTL-SDR stick and connect it to an antenna (using a band-pass filter not to overload the RTL-stick with crap).

The repeater system is based on an svxlink controller so just installing remotetrx on the RPi is enough to get started.  And since we’re hamradio operators and not internet amateurs, the remote receiver is connected via 5 GHz HAMNET. It even uses an indirect link from my house via the IJsselstein tower towards the Hilversum tower where the controller and transmitter is located.

There are still some improvements to be made and I have to mount a dedicated antenna for the system.  There is only one problem: when using my Alinco DJ-G5 triband portable on 23cm the signal, even with 100 mWatt, is blocking the receiver.

First price Belgium 144 MHz Spring contest

I won the first prize in the Belgium UBA spring contest on 144 MHz. within the QRP segment outside of Belgium. The caveat: I was the only one who send in a log :). Nevertheless I’d like to thank all Belgium stations for there patience working me. I was using about 5 Watts of power using a Ukrainian transverter behind the Icom IC-7300.

If I was sending in a regular log (no QRP) then I would have been second of the DX-stations. See you next year.

July 2017 NAC-contest 144 MHz

The first two hours I started beaming OZ and DL. Signals from OZ (and SM) where very loud. From 120 degrees (Germany Ruhrgebiet) I noticed local QRN. That’s why dots are missing in Germany. Later on I directed the beam 270 degrees towards the UK. Unfortunately no Wales or Scotland. The biggest surprise was a neighbour station a few hundred of meters away calling me. He said “Well. I guess this QSO doesn’t give you lots of points since we’re in the same locator”. Wrong! Each new locator (JO22) gives 500 bonus points. And since I didn’t work any other stations in JO22, this QSO gave almost the same points as a QSO with an OZ station in Denmark with a competitor in the same grid locator. So dutch hams. Build a Moxon (It will only costs you 15 minutes), put it on a broom and put it out of your attic window. Or take it with a FT-817 up a hill. You will work OZ, DL and G-stations and you will contribute to other competitors in the contest. Don’t have 144 MHz SSB? Visit PI4RCG. They have 2 base-stations for sale for 100 Euro each.

July 2017 VHF-UHF-SHF contest

New DXCC: SP (Poland) and EI (Ireland). The last one, I was able to work on 432 MHz in SSB and 144 Mhz in CW. Distance: 827km zo my ODX for this contest. I didn’t hear and work SM (Sweden) stations. I had a sked with an OE (Austria) station but unfortunately this didn’t work out. Maybe next time.

RSGB 144 MHz May contest 2017

Last weekend the RSGB held the annual 144 MHz May contest. I’ve made 17 QSO’s on Saturday. Just for fun. The log is send as checklog. I”ve made one mistake with G3WSK’s locator. UT1FG/MM was a surprise as operator, active from his boat on the Northsea. The band was quiet dead. ODX was M0WYB with 548 kilometers.

Preparing 23cm station

I’m preparing my 23cm station. Last weekend I’ve made some QSO’s during the May contest but with a very limited set-up. Time to have some more punch. Onboartd is a Gemini SSPA easily capable of delivering 180 Watts. More than enough for the 120 Watt limit here in the Netherlands for bands above 1 GHz. Also mountes is the SHF Elektrotechnik LNA capable of handling the same power. The todo is the antenna. I have to mount a 45-elements (5-elements reflector) 3,4 meters boom yagi for the 23cm band.

May 2017 VHF-UHF contest

Active on 144 and 432 MHz. New was 1296 MHz with a (very) limited set-up: 15-elements yagi (120cm boom) without pre-amp and 10 Watts of output power. Still able to work Belgium, Germany and England.

Antenna maintenance and QRV on 50/70 MHz

Last weekend I’ve performed some antenne maintenance. The LNA’s for 144 and 432 MHz are in place. I also mounted a small 15-elements antenna for 1296 MHz (23cm). During the contest last weekend I was able to make a QSO with Belgium, Germany and England with only 10 Watts of power and no LNA. I even heard a OK-station from the Czech Republic but due to lack of power I wasn’t able to work him.

For the Sporadic E season, a dual-band Moxon antenne is mounted for the 50 and 70 MHz bands. So with this set-up I’m able to work on 50, 70, 144, 432 and 1296 MHz and the HAMNET dish for 5600 MHz.

Special thanks goed to Gerton (PD0G) for helping me out. He was driving by for a cup of coffee while I was packing stuff to go to the roof.

N1MM+ and Icom IC-7300 Waterfall

The developers of N1MM+ software released a new build Amongst bugfixes there is one new feature to mention. Waterfall support for the Icom IC-7300. Read more on the N1MM Logger+ Facebook page or the documentation page on the website.

IC-7300 Spectrum display in N1MM+ version 1.0.6221Setup • Keep the noise level low by setting the ref level low and…

Geplaatst door N1MM Logger+ op dinsdag 25 april 2017

VHF and UHF preamps

Today the preamps for 144 and 432 MHz arrived from Wimo. They are manufactured by the German SHF-Elektronik and powered via the coax-line (My Icom IC-9100 supports 12 volt over coax). Both units have a VOX unit so no need for a seperate PTT-line (for now). Now I only have to find some time to mount them before the first weekend of may contest.


Last week we’ve reconnected the 220 meter high accesspoints in the Gerbrandy tower. Tough I’m not able to physically see the tower since it’s 31km away from my home (I can see the PI2NOS tower 16,3 km from my home) I accidentally discovered the Gerbrandy signal (PI1UTR) on HAMNET is 5 dB louder then the PI1NOS signal only halve the distance.

I turned the antenna permanent. The link looks stable with about 40 Mbit/sec bandwidth, using 5 dBm power in a 40cm dish (25 dBi gain), which makes 1 Watt EIRP in total. The ISM limit for outdoor Wifi in the Netherlands. This looks very promising since we’re busy rebuilding the PI6ATV repeater with output on 10 GHz.

I wrote an article in Dutch on HAMNET.nl.

March 2017 VHF-and-up contest

This weekend I found a few hours to participate in the IARU Region 1 March VHF-and-up contest. I started late on Saturday due to work for HAMNET and PI6ATV in the IJsseltein Tower but managed to run for about two hours. On Sunday late in the morning I found another few hours to contest. In total I’ve made 37 QSO’s on 144 and 432 MHz using low power without pre-amps. Best DX on 144 MHz: OK7O (606km) Best DX on 432 MHz: DL0HTW (573 km).