Category Archives: Equipment Disassembly

Antenna Renewal 20th April 2025

Posted by gdars on April 21, 2025 No comments

A group of us came to the club QTH on Sunday to help Colin replace/repair the antennas that had been damaged in the last few big storms.

We had a replacement cobweb antenna in the cupboard ready to be put up, and also the endfed antenna needed to be re-slung over the tree.

We got the old cobweb taken down and dismantled. Bob was going to polish and UV-coat the fibreglass poles with a view of rebuilding the old cobweb so the club could make use of it somehow.

Then the new one was mounted on the pole, unfolded, and put back on the chimney.

Sorry looking old cobweb antenna on the chimney

The new antenna covers bands 20/17/15/12/10/6/4m.

We didn’t have a chance to test it as there was another group in our room so that’s a task for next Wednesday. We also didn’t have time to work on the endfed.

Many thanks to Colin and George for the bulk of the work on the roof, and Jim, Neal, Bob and Mike for assistance on the ground.

A more productive Easter Sunday than chasing eggs!

Photos from George, Neal, Bob and Jim.

Wednesday Nights

Posted by gdars on May 6, 2023 No comments

Here are a few photos of some Wednesday night meetings’ technical goings-on. Not the same night, but several nights at the start of 2023.

Looking at several magnetic loop antennas on the table and on tripod

We had a “magnetic loop” antenna night when several members brought their various magnetic loop antennas to look at. Bob GM4CID tested them for frequency and efficiency using a MiniVNA analyser.

Also Colin MM1APS was looking inside a Kenwood TK-705 mobile set to fault find problems with it.

Opening up a vintage Cambridge Pye shortwave radio.

Old valve (vacuum tube) tester and Colin

Colin brought in an old valve tester to test some vacuum tubes for another piece of equipment.

Icom IC-756 Pro II and Icom IC-706 radios on table, 756 with case off

Colin fixing a member’s Icom IC-756 Pro-II radio. Spot the destroyed component he’s trying to replace.

Icom IC-706 radio with ATU-100 EXT tuner and portable battery pack

Frequency standard receiver and frequency counter

Mike MM3NTX brought in his Icom IC-706 radio to be frequency-calibrated because he was told it was “very slightly off” when he bought it second-hand. Colin brought in his frequency standard (receiving the 60kHz MSF signal from Anthorn) to calibrate the club’s frequency counter, and then in-turn used that to adjust the Icom. The radio was 400Hz out at about 145MHz, adjusted to within about 5Hz of frequency which is pretty good.

Old 486 PC running MS-DOS being used to program a some old Philips FM1000 radios.

John GM7MUN brought in his old 486 PC running MS-DOS as it had the hardware and software to program his Philips FM 1000 mobile sets. Bob helped him with the programming.

Club night – Colin’s 2m Cubical Quad Antenna

Posted by gdars on July 25, 2022 No comments

Colin brought in his homemade 4-element cubical quad antenna for the 2m band (144-146MHz) to test and adjust. Luckily the main hall was available so we could set everything up all spaced out and far away from human bodies to get better readings on SWR and sensitivity.

nanoVNA showing SWR of 1.0:1 around 145.050Mhz

Colin kneeling at a chair working with nanoVNA connected to his quad antenna and also a basic dipole antenna for comparison.

Everyone needs a nanoVNA for testing antennas!

He is now working on a similar antenna for operating on the 4m band (70-70.5MHz).

Old Murphy Naval HF Receiver

Posted by gdars on May 5, 2019 No comments

Old Murphy receiver given to a member by the widow of a local Professor of Electrical Engineering, who wasn’t a licensed radio amateur but according to his wife spent hours on this sitting listening at night.