Remembering Rediffusion Northampton by Tony Popple

H F
Now we look at the start of the TD70 HF system. T he system was a trial system for a synchronized carrier oven controlled oscillator with upper side-band being the first of it's kind. The aerial site was chosen in a field which belonged to Earl Spencer at Kings Heath. This was to feed areas of Duston on the west side of Northampton and Briar Hill on the south side and all areas between. More flats were built in this area from 1972 expanding Northampton even further. At the same time a new estate was being built at Lumbertubs so a new 'site' was installed with just one feeder to the estate. This system had different equipment to Kings Heath. This equipment comprised the usual FC 100's with a small audio amplifier of about 5 watts enough power to reach the kiosk at Lumbertubs site where the audio was then amplified by AA105's. The vision was amplified by AR 106's with an output of 12 volts, after a while the 'site' was made larger (phase 2) the vision amplifiers were changed to AR113's with an output 20volts .
When all of this was nearly complete Alliston Gardens was added and a further site was added at Leicester St. With AR106 vision only amplifiers. To finish the system Spencer Estate was added with AR113 and AA105A. In addition to this system a small site was set up at Exeter Place, this was known as a Midi Head End all in one system with 8 x AA 105’s for audio with a repeater AR106, vision only at Bouverie Street across the Wellingborough Road , comprising 4 UHF signals only.

1973 onwards .
After the Relay system was closed down there was no reason for staff to operate control at night so an answering machine was put in place. The stand-by engineer had to phone the machine and give a code at the end of the message, then the machine would rewind the tape and start giving all the faults to the engineer. This lasted for about a year as the HF system was about to start and night operators were re-instated. The whole of the workshop and offices then moved to new premises at Moulton Park. There was one incidence I remember on European cup final night, Liverpool against Inter-Milan when at 8.50pm I phoned-in (being on call) and everything was OK so the operator went to catch the bus home. The following morning at 8.30 when I arrived at work I did not even reach my office when the telephonist shouted to me and said the phone is red hot with calls of no pictures at Duston /Central area /Briar Hill. Off I went to Gladstone Rd thinking there was a mains failure at the kiosk or the stand by batteries were dead but found no signal coming in. I went straight to Kings Heath aerial site and found that the fuses had blown on the vision amplifiers and power supply. After quickly fixing the fault by 9.05am, I went back to receive another 50 calls for the fault which were all visited by 12.30pm . Another couple of major faults I remember include one at Duston where the system, which had only been working for a few months had been struck by lightening. It happened on a Thursday night and the equipment dept. did not know until 11.00am on the Friday. The Maintenance staff were out finding inserts blown to bits but they found after awhile that there was no signal present after the phantom supply. The wiring of all the phantom supply was checked and we found that the batteries supplying the A619A had been destroyed so my boss had to go to Nottingham to get some replacements as we did have any at the time with it being a new system . All was working by 5.30pm that evening. The other major fault was again caused by a lightening strike this time in the Central area. It started out just to be a call across the road from St Katherines depot. so I had walked across. I found people had no sound on the same block, usually a short in the switch or open circuit in the switch. I went up to the top of the roof and found the boxes concerned split open. I looked along the line and found more in the same state so I went back to St Katherines an to get some help to clear these faults. Russell Stamp the EIC and 6 wiremen came and after about two weeks we had cleared the whole of the estate finding many boxes blown and cable damage. The good side to the HF system was that when we had a technical audit, an engineer from the BBC who I accompanied said that the system was vastly superior to any other system that he had previously been to with the following result:
25% class A pictures      50% class B pictures    20 % class C   and   5% class D and the only reason for that 5% was because one subscriber visited had a noisy tuner which was not exactly a system fault. Normally the figures quoted are the other way around.

Equipment at the start of the HF system

Programmes received         VHF:    BBC1 ch4          Anglia   ch 6               Midlands ch8

                     UHF:   BBC1 ch31             BBC2      ch27              MIDLANDS       ch43             ANGLIA ch24

We had facilities to change any combination of received signals from Sutton or Sandy Heath, especially when Sandy had poor signals conditions. We used a 'cross hatch generator' when BBC2 was off air to help the TV engineers set up the convergence on the colour sets.

Kings Heath   Aerial site Equipment:    4 x Fc 100         and       2 spare       Fc100v's,     3 x A529 405 receivers
                                                           Oven Controlled oscillator 5.9 MHz., 7 x AR105, 8 x A623 150w Audio Amps.

Local Kings Heath area      7 x AR 102,    8 x A623 audio amps , output transistors OC 28 direct fed.

Duston 8 x A623, 7 x AR105    Gladstone Rd 7x AR 101   St   JamesPark Road 7x AR 101