George M1GEO and myself took part in the RSGB 70 MHz trophy contest this weekend at the Kelvedon hatch Secret Nuclear Bunker contest site. The weather was ideal for alfresco operating, using the Icom 7100 and homebrew 6e beam at 10m on the Racal PU12 mast. Using 50w and a 85Ah leisure battery we operated from 11am till 4 PM.
Here you can see the PU12 and home-brew 6e 70 MHz beam. Operating from the base of the mast provided quick access to turn the beam. We managed to work 59 QSO with best DX into Scotland at 518 KM. The QSO map is shown here.
Meanwhile Rob M0VFC was operating QRP HF on 3.5, 7 and 14 MHz using a range of dipoles. Unfortunately the HF bands have been a challenge at the best of times during the day, and QRP provided to be interesting. After a few hrs operating Rob had completed 30 QSO, and under the conditions that counts as a sterling effort ! Here you can see Rob operating from the boot of his car Altogether another great weekend of alfresco operating in the sunshine.
Spent a very enjoyable Sunday with the crew from Essex Ham. The operating site is at Gallywood common near Chelmsford, and the operating is outdoors and subject to weather. The sun was shinning, and alfresco portable operating was possible.
Stations included 2 HF, 1 VHF/UHF and 1 on 70 MHz. I opted for the 70 MHz station, using a Icom 7100 and a slim Jim supported on a spidebeam roach pole.
Here you can see various various roach poles supporting HF and VHF aerials.
Over the afternoon I worked 12 stations on 70 MHz, they ranged from Southend, Colchester and Waltham Abbey so around 20 miles.
Band conditions on HF left a little to be desired, although this didn’t stop Peter G0DZB from working CW on 10 and 14 MHz.
Many thanks to the Essex Ham team for their hospitality, bacon sandwiches and tea. I hope to see you again soon on another sunny afternoon for some further portable operating.
The project was to build and test a 2e Quad antenna for 14 MHz, I wanted it to be lightweight and portable. The antenna had to be packed away in the car after a contest, so some parts of the antenna had to conform. The boom could be no longer than 3.5m, and the spreaders must be retracted for storage.
Cost should be under £100 for all the parts delivered.
The design uses fiberglass fishing poles, each pole is 4m fully extended. The project uses 8 poles. The poles will be fixed to the centre clamp using exhaust brackets, as they come complete with “U” support bracket. The size of the exhaust clamps will depend on the size of the roach poles.
The aerial will be 8m long, and 5m wide (see diagram) and the feed point will be at the bottom of the driven element. You may require some matching at the feedpoint, although mine was close to 50 Ohms.
You can find many online quad calculators, one that worked well for me is located here.
Here you will see the basic quad element, the basic construction is the same for both the driven and reflector. Here you will see the basic layout.
Photograph of parts required. (Click to expand pictures)
Having fun with the Quad and linear amplifier. QRO HF portable
A long weekend away in Cromer, time to close up the static van for the winter and hopefully some time for /p. This time I wanted to try a 20m endfed wire, this ran from the tree at the back of the van into the ATU. I connected up another 20m wire and connected that to the earth of the ATU. The antenna seemed to work quite well on 7 MHz and would even load easily on 3.5 MHz (working as a 1/4 wave). I decided to try my luck and load the antenna on 1.9 MHz, as this weekend saw the RSGB club calls contest.
Despite doing a really good impression of a spark generator I did manage to work 20 stations around the UK. The best DX for the weekend was working into South America on JT65 on 3,5 MHz.
Also had a nice QSO with Peter G4VLC on 5.3665 MHz Olivia. Once again goes to show 10p of bell wire may not make the best antenna in the world, but it sure beats the £149.99 Chav 1.
The popular shortwave and ham magazine Practical Wireless runs a 70 MHz contest once a year. The contest attracts a number of entries from all around the country, including one keen team who climb Helvelyn in the Lake District (M0BKQ/P). The entry from M0TAZ/P didn’t include a 900m accent to the top of a mountain, we operated from the JO01 Kelvedon Hatch Secret Nuclear Bunker near Ongar Essex. The location is over 100m ASL and affords nice views over the Essex countryside.
The activity started at 1PM and finished at 5, activity levels were moderate with the first 2 Hrs being the most active. Many portable stations operate 10w or less so the amplifier and 160w did mean we sometime had to listen very hard to get a calling stations details. Sometimes people assume that because they can hear you loud and clear their signal must also be good.
The weather was sunny, and this must have helped encourage people to operate portable outdoors.
We managed to work 47 stations our best DX being Scotland GM4JR at 454 km and was pleased to work into Wales GC0VPR/P, GW0EIY/P and GW4EVX/P and also the Netherlands PA4VHF.
The QSO map pins indicates the location and number of stations worked.
Many thanks to John M0UKD for the use of his beam and 70 MHz amplifier, both worked flawlessly and George M1GEO, Dave M0YOL and Chris G8OCV for assistance with the mast and words of encouragement.
Thanks to everyone who called, and hope to work you again soon 73 Dave M0TAZ
An afternoon in the sun looked like an ideal opportunity to work some station on 70 MHz. Bedsford park is the highest point around at the dizzy height of 100m ASL. I decided to take the 12m roach pole and Icom 7100 and the slim jim.
The portable trolly, battery and antenna.
After setting up the radio, powered by a 90Ah leisure battery my first visitor was the local parks patrol. They have recently been kitted out with a look alike “emergency” response vehicle, complete with blue lights and checkerboard markings. We had the usual chat that started along the lines of “Have you asked permission” … (oh this isnt going so well.) I didn’t quite work out why I need to ask permission to sit in the park with a fishing pole and Icom radio, it seemed like the local dog walkers with their poop machines or the kids throwing sticks into the conker tree was just fine but thats another story. He was quite amicable once I told him I was a licensed amateur radio operator, either that or he was just confused by the term.
Sitting on the park bench
Anyhow, after the passing of the parks police enforcement team. I got down to some operating, calling CQ on 70.450. It was great to hear so much activity, and I quickly worked 12 stations.
I managed to work.
M1COI – Henry- Belvedere
G3XFE – Chris – Eastbourne / Tunbridge wells
G8YNC – Peter – Alexandra Palace
G3VSJ – David – Hoddesdon
G4UAQ – Ian – Maidstone
The Slim Jim up 12m on the roach pole.
M0KSJ – Kevin – Chislehurst
G3VPS – Peter – East Grinstead
G3RQZ – Peter – J6 M25 Godstone
G8NDL – Ken – Swanley
G8KQA – Roger – East Sussex
G7CRQ – Adam Wallington.
A very enjoyable afternoon, thanks to everyone I worked 73 M0TAZ