Thursday, 26 November 2015

Close call for local radio club.

The Drogheda and District Ham radio club had a brush with danger as their 4m (70Mhz) DXpedition to Central Papa New Guinea had to be cancelled. While flying over the island looking for the landing strip Tony EI4DIB, the head of the expedition heard a sudden thud on the underneath of the aircraft, suddenly there were several more thuds.
The pilot then reported that he was having trouble with the landing gear and he would have to abort the landing.
When the 4m expedition returned to base the reason for the thudding and the landing gear issues were suddenly exposed, the underneath of the aircraft had more than several dozen primitive arrows sticking out of it, the arrows were later identified as arrows from the Korowai Tribe, also called the Kolufo, a people of south eastern part of the island. 

Korowai Tribe.

When interviewed about the incident Tony was evidently shaken by the whole event, as to why the Korowai Tribe attacked is debatable as they are a very reclusive cannibalistic tribe. There may be a few reasons for the outburst, one line of thinking is as they do not like outsiders that they were reluctant to let the airplane land, the other line of thought is that they were trying to bring down the plane as it was full of “plump” soft skin Irish men, (which is a delicacy to them).
Whatever the reason is Tony is sure it has nothing to do with them operating 70Mhz on the island without the proper permit….

Wednesday, 25 November 2015

Anthony EI2KC works his first 4m (70Mhz) contact into Poland.

Many National and International Ham Radio Operators are familiar with Anthony EI2KC, he may not be known personally by ham radio operators around the world but his Callsign has adorned their logbooks since his induction to Ham Radio on the 30th October 2009, After passing the Morse test in February 2010 Anthony upgraded his Callsign from a 'B Call' to an 'A call' and was given EI2KC on March 5th, the world has never been the same again….
Anthony has a great love of anything HF and is very proficient in CW (Morse Code), he has worked many countries, and loves to get that rare hard to get one into his logbook.
Just recently Anthony received an Award for First Place, single operator unlimited mode, Low Power Ireland on 10m from the ARRL .

Anthony, who is quite modest about his achievements on HF was quoted in saying “Nice surprise in the post. Totally unexpected!”
Anthony is also a keen operator on the 70 Mhz band and has been known to spend many hours trying to make a contact.
To his delight recently while calling out on 70.400 Mhz for some local hams he got a surprise when he was greeted by a “SP” Callsign coming back to him, after a short exchange of information and both operators putting each other’s callsigns into their logbooks, Anthony and the “SP” station exchanged some pleasantries.
After the contact was done, Anthony rang me on the phone, he was quite excited about the contact, he told me that it was better than working  VK9WA Willis islands or indeed S79C DXpedition to Coetivy Island.

Anthony plans to get more active on 4m in 2016 and told me that “HF may take a back seat for next year”.

Monday, 23 November 2015

70 MHz beacon list in SP.

Because of some inaccuracies in Cluster Spots and wrong calls, below is a updated list of Polish 70MHz beacons - July 27, 2015.

70.100.2   SR3FHC/B   JO92AD    F1A   8W   BIGWHEEL           SP3QFV
70.102.0   SR8FHJ/B    KN09RR   A1A  1W   CROSS DIPOLE    SP8WJW
70.105.2   SR2FHG/B  JO94II       A1A   5W   TURNSTILE           SQ2BXI
70.110.0   SR5FHR/B   KO02GH  A1A   5W   TURNSTILE           SP5XMU

70.119.2   SP7VC/B      JO91SS    A1A   5W    TURNSTILE *off during Balkan trip 2015
70.120.2   SP3RNZ/B   JO92DF    A1A   10mW  1/4GP 

Wednesday, 18 November 2015

ZS2EZ'S 70MHz in South Africa.

Background: The 70MHz (4m) band was introduced to South Africa in 2003. At present we only have SECONDARY STATUS, i.e. the band is shared with commercial users who have priority and we have to accept interference from primary users. On FM 12.5kHz channel spacing is mandatory.

Thanks to John ZS6JON, I obtained a Ranger commercial midband 16 channel FM radio programmed for the 70MHz band back in 2003 whilst living in Johannesburg. For an antenna I used a second-hand Webb commercial midband dipole, up on my tower at around 8m high. John and I were the first two stations active on this band in the Northern areas of Johannesburg (John lives in Krugersdorp, some 30km from my home in Jukskei Park), and utilized this band as a kind of "radio telephone". By the time I moved back to Port Elizabeth there were a few more stations around, but the band was still sparesly used.

Upon arrival back in Port Elizabeth, I found a number of local stations showing an interest in the 70MHz band. Many of these operators were using ex-miltary radios (which sounded terrible), but thanks to Ken ZS2OC many had equipped themselves with ex-commercial AS1000 and Pygmy radios. Ken was also supplying endfed vertical antennas and custom-made wire-and-aluminium beams (Ken referred to these antennas as "junglejobs"!). VHF enthusiasts Al ZS2U and Mike ZS2FM soon began experimenting with beams for 70MHz, and their keen promotion of the band soon saw the numbers of operators increase. An example of this can be seen in the distances recorded in the annual PEARS VHF Contest: during the 2005 event (the first to include 4m) ZR2DX and ZR2GLP achieved the longest distance of 11km on this band. In the 2010 event the longest distance was 1183km, between ZS2ACP in PE and ZS6WAB in Polokwane!!
For myself, I was frustrated at being restricted to FM-only operation. Others (notably Andre ZS2ACP and Paul ZS6NK) were experimenting with SSB and Digital operations, and I found myself ignoring 70MHz for several years. When my endfed vertical broke, I made no effort to replace it, and my 3 element "Junglejob" was left lying on the roof.

All this however changed in 2010 when I replaced my backup/6m radio, a Kenwood TS-570S, with a mint-condition Yaesu FT-847. Andre ZS2ACP very kindly did the 4m modification for me, and I ordered a 70MHz in-shack preamplifier from Spectrum Communications in the UK. On 4 August 2010 I tried my first 4m WSJT sked, with Paul ZS6NK in Polokwane. After the modification I get around 50W from the FT-847, and Paul was able to copy my signal. Unfortunately my antenna (the 3-el Junglejob) just wasn't quite good enough (a few very weak pings and fragments of callsign were all that was copied at my end).

Having established that my antenna was simply not good enough, I turned to my good friend Basie ZR2BA for assistance. Basie has just recently built a 5 element 70MHz LFA Yagi, from the design of G0KSC. I had planned to build one of these myself in the next few months, but quite simply was too pressed for time at the moment. Basie then kindly offered to build one identical to his for me. I managed to sneak a bit of time off work on Thursday 5 August 2010 to buy the necessary components, and on the afternoon of Saturday 7 August Basie delivered the completed antenna! He then helped me to put it up on the same pole that had supported the "junglejob", and the SWR read at 1.4:1 across the band - quite satisfactory!

The antenna is fed with LMR400 (pigtail and choke balun is RG-213, joined to LMR400 via barrel connector just below u-clamps securing antenna to pole), and the flylead between the preamplifier and radio is also LMR400. A quick on-air test with Andre ZS2ACP showed that everything was working well. 
The real test came on the morning of Sunday 8 August, when I had a sked with Paul ZS6NK in Polokwane (1 178 km away). This time my efforts were rewarded with solid 3dB pings almost immediately! The QSO was completed with relative ease, and towards the end lengthy bursts were received!
Screenshot from ZS6NK showing copy of my signal.

With the completion of my contact with Paul ZS6NK, Andre ZS2ACP called and worked him. During Andre's QSO Paul was even louder here than when I had worked him! Their QSO took a total of 3 minutes!!
During 2013 the LFA antenna was installed on my main tower, between my two Cushcraft HF antennas. This is at a height of approximately 55ft. Feedline is LMR400, with a Telegartner lightning arrestor in line just before the entry into the shack.

The Spectrum Communications (UK) RPS4 Preamplifier.
The 70MHz LFA mounted between the HF beams.

Tuesday, 17 November 2015

50 and 70MHz homebrew SSB transceiver with SDR output.

David Kearns Near Chippenham Wiltshire demonstrates his 50 and 70MHz homebrew SSB transceiver with SDR output.
This is his homebrew Six & Four Metre transceiver. Here working a station during a Four Metre, 70MHz contest. The rig has an SDR output. which can be seen driving #SDR. It has an output of 2 Watts which is enough to drive the homebrew amplifier to 125Watts. Power out on Six is 10Watts which give me 150Watts out of the Six Metre amp.More on his website, search G8TTI

Sunday, 15 November 2015

Radios Used on 70Mhz through the years.

A brief view of some of the radios that were used on 70Mhz (4m) through the years, if there is anything here that you may have or had please email me with photos or details of conversions. 
All photos below are courtesy of

Click on each image to enlarge.