HAMNET QSY to PI1UTR

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).

New rotatable tower

Today I’ve made some progress by replacing the antenna tower on the roof. It’s now rotatable. The Diamond X6000 has been replaced for the X5000 so the total length doesn’t exceed the 5 meter due to regulations to keep it license free without the need for a building permit. The 9-element LFA for 144 MHz and the 19-element LFA for 432 MHz are installed. The 120 cm dish for 1296 and 2320 MHz is on the todo list after there is some more counterweight placed.

Special thanks to Remco (PA3FYM) for helping me out.

LFA-power

LFA-power

Thanks PA3FYM for helping me out.

Thanks PA3FYM for helping me out.

HAMNET live

The HAMNET connection is live. It’s not VPN based, but radio based on 5 GHz. I’m using an Ubiquiti Nanobeam M5-400 with 40cm dish to have enough gain towards the TV tower located about 16km from my home. Line of Sight is (just) availlable which is mandatory for a 5 GHz connection.

The dish needs to be moved up a meter or so since the flat roof is in the fresnel zone. Horizontal signal is about -85 dBm, vertikal about -81 dBm. Since I’m using cross polarity, +3 dB can be added making the total signal received about -80 dBm. Enough for 19,5/19,5 Mbit/sec with 10 MHz bandwitdh. The goal is about -75 dBm signal.

ATV station for 5700 MHz (6cm)

The new ATV station for 6cm consists of:

  • 23cm UniTX transmitter for 1400 MHz uplink
  • DG0VE Frequency multiplier
  • DG0VE amplifier: 60 mWatt > 600 mWatt
  • Final amplifier: 150 mWatt > 14 Watt
  • SMA coax relay to switch between TX and RX
  • RX converter 5,7 -> 1,0 GHz with pre-amp
  • Some sensors for temperature, fan control, etc

The complete set-up (excl. antenna) is mounted in an outdoor enclosure. Any 75Ω satellite coax can be used as transmission line since losses are low due to the 1400 MHz uplink and 1000 MHz downlink. These frequencies are outside of the 23cm band so there shouldn’t be any interference. For the last 2 meters between outdoor unit and antenne, Aircom Plus is being used with a length of about 3 meters. The unit is powered by 12 Volts and 4 cables to control the unit are going down. Any decent outdoor UTP (STP) cable is sufficient for this.

I’m able to receive om 23, 13, 9, 6 and 3cm and transmit on 23cm (low power) and 6cm (medium power).

img_1670

Building an 13cm SSPA

With a few hams on the club we’re busy building 13cm SSPA’s. The base equipment is ex 3G/UMTS equipment. There are two models availlable for around 10 euro’s and can be found on ham flea markets. The small module has an output of about 30 Watts, the big modules output is around 90 Watts. on 2140 MHz. Both are usable on 2350 MHz. First, let’s have a look at the stages and modules used. Goal is to use the SSPA for the Es’HailSat 2 uplink. See PA3FYM’s website for details about antennas used for this project.

IMG_1335

From left to right we have 2 modules on the 30 Watt SSPA, 3 on the 90 Watt SSPA. I’ll write down the details of the 90 Watt SSPA. The 30 Watt version is the same, but the last stage is missing. The input (left) is +5 dBm (3 mWatt) and is feeded into an MHL21336, the blue module. This has an amplification of 31 dB and is feeded into the second stage, an MRF21030S with an aplification of 13 dB. From here, it goes to the final stage to add 5 dB more gain using an SRF7068H5HS (MRF21085S?).

I’ve created an bypass in the first stage. The output of the LZ5HP transverter is about 2 Watts and, altough 1,5 dB to less, enough to feed the second stage. The alternative was to attenuate the TX-signal from the transverter with 30 dB from 2 Watts down to 1 mililWatt. Additional benefit is that the first stage (blue module) has an aplification of 31 dB wich will result in difficulties in the housing due to howling and crosstalk. By bypassing this module, that problem is solved the easy way.

All is powered by 28 Volts (DC) and still work in progress. To be continued.

Remco's (PE1PIP) result...

Remco’s (PE1PIP) result…

Hytera MD785(G) noise modification

The Hytera MD785(G) DMR transceiver works great out of the box, both analogue as digital. But there is one problem. Noise coming out of the speaker. Even when the tansceivers audio gain botton is set to zero. When the squelch opens, noise can be heard. There is no way to fix this in the firmware of CPS codeplug by programming.

The modification is to put a 22 Ohm resistor in serie with the speaker. So, hardware needs to be mobified. The good news: The modification is easy and no SMD needs to be soldered. Just remove the front of the MD785, carefully remove the flatcable and put a 22 Ohm (variable) resister in series with the red speakerwire. That’s all.

Now reprogram you radio and set the speaker output level for both analog and digital by +2 or +3 db as compensation for the resistor you’ve just placed. Upload the codeplug and you’re done. The noise is gone.

Step 1: remove the front and *carefullly* remove the flatcable if you need more space.

Step 1: remove the front and *carefullly* remove the flatcable if you need more space.

Step 2: Put a 220 Ohm (variable) resistor in serie with the red speaker wire.

Step 2: Put a 22 Ohm (variable) resistor in serie with the red speaker wire. Adjust the resistor if you feel the need to do so by a few Ohm.

Welcome 13cm band SSB

Since last month I’m QRV on 2302 MHz to, with help from the LZ5HP transverter. Next is to build an SSPA based on ex 3G/UMTS equipment. The modules and 24VDC PSU is there. I only need to find the right heatsink.

LZ5HP_13cm

Bluestack and BlueDV: Hotspot in a box

Developments for DMR and D-Star hotspots go fast. I already owned a UHF hotspot from PE1PLM which fits on top of the Raspberry Pi. With custom firmware, this also works with MMDVM software thus DMR. A new toy is the BlueStack, developed by PE1MSZ and sold via CombiTronics.nl.

Put the DVMEGA (UHF) transmitter on top of the BlueStack, install BlueDV on your Android phone and the unit connects via BlueTooth to your phone and from there to the D-Star and DMR networks. I don’t have to tell you that a USB power pack will give you a full portable hotspot. Nice for the car, on holidays or in the offices. Good work guys!

Update: To communicate via such a hotspot, a transceiver capable of the used DV mode is necessary to operate, the hotspot provides only an access gateway to the selected infrastructure. The hotspot has only one time slot. At the moment, the subscription on BrandMeister is dynamic and valid for 15 minutes.

A complete portable D-Star and DMR hotspot

A complete portable D-Star and DMR hotspot

New house: Welcome back VHF UHF SHF

I’ve bought a new house and will be moving over end of september. The good news: It has a big, flat roof to put my VHF, UHF and SHF antennas on top of it. The other good news: The 3 story high building itself is about 9 meters in height, but it’s on top of a hill that also is about 11 metes heigh, overlooking the area which is a must-have to be succesvol on microwave bands. So the antennas will be on, lets say, 22 meters above street level.

A view to the north from the 2nd floor. Antennas will me +10 meter? You can see the city of Bunschoten Spakenburg.

A view to the north from the 2nd floor.

A view to the south from the 3rd floor. Antennas will be +5 meter? You can see the city of Amersfoort.

A view to the south from the 3rd floor.

I guess that means the end of HF for a while since I want to concentrate on the VHF and up bands. The gear is there to work on 6, 4 and 2-meters, 70, 23, 13 and 6 cm (and RX on 9 and 3cm). I have to build a transverter for the 9cm and 3cm band. Power is minimal, but RF-pallets and ex UMTS/3G network gear will do that for you. I’ve already collected 30 and 90 Watts 2140 MHz modules that can easily be converted to 2300 MHz.

Update: Moved over end of September. New panorama photo’s taken during a roof inspection.

west_to-east east-to-west

Yeasu FT-817ND as IF transceiver

FT-817NDTo work more portable on UHF+ and SHF (and to have a nice transceiver to feed the LZ5HP 13cm transverter) I’ve bought an Yeasu FT-817nd at the Hamshop. Within two days, the 0.5PPM TXCO arrived from England via Ebay.

I bought tis unit because the IC-9100 isn’t a great transceiver to use with HF. As well as others, the IC-9100 had problems with RF spikes just miliseconds after pushing PTT. This can damage your transverter.

Last minute VHF contest

Last weekend, VERON held her VHF-and-up contest together with other radio societies throughout Europe. Since I was bored anyway I’ve collected some stuff and wen’t portable for an hour and half. Things didn’t go smooth.

13199422_10207917748693853_1329898317_oI switched the 70cm and 23cm beam feeders, only noticing during break down. That’’s why 70cm didn’’t work at all and 23cm only worked domestic. On VHF (2m), my small 5-elements beam had a bad VSWR (1:3) so I was forced to work with 10 Watts QRP.

Still, I was able to learn and work some stations, including HB9 with minimum gear. Too bad there are only a very small number of active stations in PA on the higher frequencies. That group includes me due to antenna restrictions but since I’ve bought a new house and will move over September / October this year I’m able to get some antenna’s back on the roof and be active on 6/4/2/70/23/13 again.

CQ-WW-DX CW contest 2015

CQ-WW-DX-CQ-sumThis weekend was CQ-WW-DX CW contest time. I spend some hours on the radio, in between other activities. My goal was to make about 100 QSO’s on each low band but I didn’t want to spend the night behind the rig. So the score is very low for the 160-meter band.

The 10-meter band was open but my antenna is to long for it. I did however work Australia, but an missing US and Canada (zone 2, 3, 4, 5) and the Caribian (zone 8 and 9). Due to heavy wind I wasn’t able to put up the Moxon antenne for 10. The results on 15-meters are okay, the 20-meter band had better times in the past.

Continue reading

1st during CQ-WW-DX SSB?

CQ-WW-DX_SSB_2015The raw scores from last months CQ-WW-DX SSB-contest are availlable. Tough I was operator at PI4AMF I also spend some hours making QSO’s from home. In total 200, QRP-assisted.

Seems to be enough to make it till the 1st place in the Netherlands if you rely on the RAW scores (search for PH4X).

Tropo on VHF

No. The map below is not the map with the route asilum seekers are taking from Syria towards rich country in Western Europe. It’s a real-time map showing tropo ducts on VHF. This data is bases on APRS stations transmitting there GPS-position on 144.800 MHz. You should save it on your bookmarks is active on VHF and UHF! The URL: aprs.mountainlake.k12.mn.us.

Tropo