Introduction

The Tale of a Marconi HR24 Receiver by Geoff G7KLV

The Sandford Mill collection of Marconi equipment continues to grow steadily. All sorts of equipment comes to light as garages are tidied and lofts are cleared. Marconi Veterans Jim Leadbitter and Peter Turrall are both regular donors. We have a very comprehensive collection of early TV cameras and a superb collection of maritime equipment displayed in the Ship’s Radio Room. However, I think it would be fair to say that our piece de resistance, apart from the Writtle Hut, is surely the 30KW SSB Self Tuning Transmitter! With the most amazing luck we have recently acquired the perfect complement in the shape of a double diversity HF receiver of similar vintage!

Readers of ‘Radio Bygones’ will know that one of its regular contributors is Michael O’Beirne G8MOB.   On February 10th. this year Michael sent me an email saying that there was an HR24 receiver in Ireland as Brendan Minish EI6IZ had recently inherited some radio equipment from a friend, Don Gibbons EI5IA who had passed away.   After various suggestions, Brendan said that if we could cover the expenses of his ferry crossing and diesel from Holyhead to Sandford Mill he would deliver it personally. While he was over here he could combine it with a visit to the Kelvedon Secret Bunker and the rally at Elvaston Castle.   Geoff Bowles agreed to do the necessary and it was delivered to the Mill on Friday June 8th .

I had arranged a reception committee of Club members and it was unloaded and re-assembled in no time at all!

The rack in Brendan's van.
Photographs by John, G8DET

The Rack proved far too heavey to move with the equipment insitu so it had to be taken apart.   It actually weighted nearly 500 lbs.
Dr Geoff carring one of the Receivers to the chairs where they were placed by the 2MT Hut.

Friend of the Museum, David Goodridge carrying another.

          Denis & Harry carrying another unit - heavy!

Having stripped the Rack of its units it was (just) possible to get it off the van using wooden rollers.

Here Geoff, G3EDM (left) & David are pulling it off the van.
Michael Hayes, EI2EO is on the extreme right.

Having got it off the van & into the shed, the problem was to get it upright. Fortunately the rack came with a very sturdy roller castor base which had been designed for the HR24 to enable it to be moved around with no danger of it falling over.

Tupp 3 & Heave!

Bolting it to the Roller Base
Geoff, G7KLV looks very worried!

Close-up of one of the Receivers while placed on a chair.

Geoff looking at the Receiver he assisted with the design.

Brendan & Geoff Bowles lifting a Receiver into place on the rack.
Each piece of equipment slides on runners like a kitchen drawer - very
useful considering the weight of each.

Geoff Bowles looking at the rack - all that is missing are the 2 PSUs.

Brendan (left) & Michael standing by the now assembled HR24 Rack.
A wonderful acheivement to have brought it from the West Coast of Ireland to Essex.

The whole Installation Team, minus John, G8DET, the photographer.
From left to right. Denis, M0FHA; David Goodridge; CARS Club President, Harry, G5HF;
Club Vice President, Geoff, G3EDM; Geoff, G7KLV (Designer of the HR24);
Dr Geoff Bowles, Keeper of the Museum of Science & Industry;
Brendan, EI6IZ and Michael Hayes, EI2EO.

This really is a piece of equipment. Built like a battleship & capable of running continuios for years.
Notice that on its bogey it towers above the 30 kWatt TX.

Considering the receiver is about fifty years old it is in remarkably good condition externally, although a little dusty and grubby inside.

Brendan had said he would like to meet some Club members, so after unloading and a look round Sandford Mill we took him and his travelling companion Michael Hayes EI2EO out for an evening meal at the Chelmer Tavern, and spent a delightful evening with them!

I have to admit that I was not only very keen to acquire he HR24 receiver for Sandford Mill, because it represents the last of the really big Marconi valve receivers, but also because I was intimately involved with its development in my mid twenties in the late forties!   I had the good fortune and pleasure to work for a number of years as a Technical Assistant to the late Dr.George Grisdale. G5GZ.   He was one of the team responsible for the design of the CR series of receivers, the 100, 150 and 200 and derivatives, at Baddow during WW2. George was one of the most delightful people to work for and the few years I spent with him were amongst the most interesting and rewarding periods of my working life.   I think it will be obvious why I was so keen to acquire the HR24!

My Monday Morning museum task is to get it up and running.   One of the two power units is now powered up and working (21st June 2007) with the second one on the bench.- stand back!

The target for a working Receiver is August when it will be on show to visitors for the first time!

Write-up by Geoff, G7KLV.