Showing posts with label g5um. Show all posts
Showing posts with label g5um. Show all posts

24 Aug 2022

5m recording by G5UM

Many years ago Jack Hum G5UM gave a talk to the Cambridge radio club (CDARC). In the talk he mentioned he had made a recording in the late 1940s of the last hours on 5m in the UK. I am not sure if this was a disk, wire recorder or tape, probably a disk.

I am wondering if copies of this historic recording still exist? At the time I think G5UM lived in London.

Many will remember Jack as the columnist of the "Four Metres and Down" column in RadCom.

2 Aug 2022

5m recording from the 1940s?

In the late 1940s a recording of the very last night in the UK on 5m was made by Jack Hum G5UM, who lived in London, I think, at the time. I wonder if copies of this historic recording still exist?

16 Apr 2012

My old 2m AM rig

This morning, whilst clearing out some paperwork I came across this old B&W photo showing my 2m AM transceiver from the mid 1970s. It had a tunable RX covering 144-146MHz using a free-running VHF VFO (perfectly fine for AM use) and a crystal controlled transmitter; if I recall correctly, it had a few crystals that could be switched. The TX put out around 500mW of AM and was based on the PF2AM transmitter by Pye Telecom, a project I was involved with at the time. It was built in an aluminium box covered in wood effect Fablon.

The rig was also used for CW, goodness knows how, by having an external BFO held near the rig to demodulate a CW signal. Drift was a major issue on CW as you can imagine! Using this Heath Robinson arrangement I had a weekly sked with G5UM some 80km away every Monday night for several months and regularly received 559 using an HB9CV antenna in the loft.

The rig worked some useful AM DX across the UK with the best DX from home being a station in northern France one evening but it was really used as a local natter box in the Cambridge area.

When the ubiquitous Liner-2 2m SSB rig appeared I managed to buy a second hand one and this homemade AM rig was abandoned. I cannot remember what happened to it. It is nowhere to be found, so was probably taken apart for bits, which was a pity. Today I still use 2m AM from time to time and it remains a perfectly acceptable mode for local contacts with very simple kit.

1 Sept 2010

Last days on 56MHz (5m) - lost recording?

Many years ago Jack Hum G5UM attended the Cambridge club and talked about VHF. During the talk he mentioned a gramaphone disc being made recording the very last night of operation on 56MHz in the London area in the 1940s. Does anyone know what happened to this most historic recording?  This would be a wonderful item of ham history if it could be located.