As it's been cold, wet and windy today I investigated why my Leak tuner was apparently not working on Long or Medium Wave (AM) and thus unable to receive Radio 5 Live...
On AM the tuner appeared completely dead...
Leak Delta 30 Tuner
This tuner lives in the lounge and feeds my PW Winton stereo amp...
On initial inspection I was mystified why the tuner appeared to have no aerial for LW and MW reception... I'd have expected to see a ferrite rod in there...
Where's the AM aerial?
A look at the service information showed that Leak had been very cunning and arranged that the outer braid (screen) of the VHF/FM aerial coax. feeder would act as the AM aerial :surprise: Once understood it made perfect sense as in its day the VHF/FM aerial would have been a substantial affair lashed to the chimney keeping the TV aerials company and thus would have had a nice long length of coax. down to the tuner and thus a very good AM aerial too...
As I live in an area of very strong VHF/FM signals (the TX is only about 10 miles away on top of a local hill) I'd never bothered with a 'proper' VHF aerial and just used a short length of wire stuck into the centre contact of the aerial socket...
When the tuner was offered a reasonable length of wire connected to the outer of the aerial socket it all worked, albeit a little deaf
A little realignment of the AM front-end brought about superb performance
More study of the service information shows the tuner has two very unusual features on the AM side: muting (squelch) to supress any audio output when no station is being received at reasonable strength and a dual-gate MOSFET RF amplifier ahead of the AM mixer/local oscillator...
The muting explains why the tuner seemed so dead on AM before I understood the rather unusual AM aerial arrangements...
I remember the Quad demos at the hi-fi exhibitions at Heathrow and London hotels - the Russell was a regular.
Quad 33 and 303 rings a bell.
The electrostatic speakers were the first time I heard a piano actually sounding like one!
IIRC, sound source for many of these demos was a Revox tape deck.
And all well beyond my pocket money!
Not exact but this is virtually identical to the reel-to-reel home tape recorder we had in the 1960's.
We still have it somewhere, with those Scotch reel-to-reel tapes no doubt filled with nostalgic gems, as well as no doubt quite awful quality recordings of top of the pops from the television, or the top 20 from the radio.
Nice clunky controls with satisfying mechanical noise on all counts. The fast forward and reverse, forward to play. the record buttons to press, and the dancing record level display. various wires connectors and robust metal microphone with coloured little jack plugs. I used to shove the mic into my brothers acoustic guitar, and yes hey presto an electric guitar of sorts
That tuner being a Leak just added to my ident difficulties Jim. We sold mostly Quad and leak in London where I worked in '54. Mono of course!
I bought my first tape recorder while I was working up there from one of the previously government surplus stores. I was a Truvox deck + amp + case and speaker. Excellent deck mechanically had separate motors for each spool and capstan, rewound at about 60 mph which was very good unless the tape broke. You had to change the capstan wheels to swap speeds. Not brilliant quality but not bad for the day. I have an almost identical Truvox deck in my workshop which is even older, maybe 50-51.
Never had what you would call a 'professional' machine but the Philips EL3542 was brilliant for the time, 3 speed four track, 15 Khz at 3.75 IPS and 20 Khz at 7.5 IPS. I still have quite a number of tapes recorded on it, mostly David Jacobs 'Pick of the pops.
I acquired a Truvox R7 (half-track mono, bi-directional rec/play, 10W valve amp) in 1966, when it burned out its 3-speed inductive capstan motor - a Swedish or Swiss jobby, unhelpfully rated at 220v (and something which I never got round to sorting, but just put in a new motor). That had 3-motor warp-speed rewind, too, Peter!
At the time (late 60s) also had use of a newer mono Truvox R101, and a stereo R102 - VU meters rather than magic-eye - but decent machines.
Years later (late 70s) the R7 was cannibalised to create a stereo deck, with a pair of rec-play boards and VU meters. The troublesome capstan motor (burned out again) was replaced with one from a Ferrograph Series 7, with speed change done by a d.i.y. belt-shift on to the R7's 6-inch diecast flywheel. Even the deck of the R7 ws sturdy: a solid slab of machined-out 6mm aluminium! It was a first, but mechanically unsuccessful, foray into building a stereo tape deck.
Although the mechanics of it were shaky, we were daft enough to try again with tape. This time an ex-IBM Potter Instrument mainframe tape deck. This hefty piece of data-room kit must have cost zillions when new, but we bought it for a mere £30 from a computer junk shop in Southampton. It was 3-motor, 1HP (!) fwd and rewind motors, and shock-absorbing transport for its ½" (10" reel) tape. We tamed the wild speeds, and opted for 15ips operation. Like Ferrograph Series 7, fast-fwd and fast-rewind became a single button press, with a rotary control for fwd-rev direction and speed. Unlike the previous R7 rehash, the mechanics of all this performed immaculately.
It was to be an 8-track 'studio' configuration, for use by the school's music department, and the VCS3 synthesizer there, as well as general recording. We built in a mixer, which allowed mix-down of tracks to each other (eg 6 mixed down to a stereo pair), for go-again, and this worked.
We bought a few reels of Ampex GrandMaster ½" tape, and had some 8-track record, play and erase heads made up for it. We had on-going problems with recording bias levels, and managed to burn out one of the record head windings. Lots of tests using signal generators, 'scopes and a record-deck as a music source - we must have worn out a 45rpm copy of Song for Guy!
In the end, it worked, but remained a 1cwt+ lump, which was utterly out-paced by some commercial 4-track machines, and - very much later - by digital recording and mixing. We learned a lot from it, not least about the limits of our own skills.
Indeed, very interesting Chris! Enjoyed reading that immensely
I never met those massive computer tape decks in my computing activities at work and exposure to tape as restricted to DAT and DLT backup devices...
I did have lots of experience of the big CDC cartridge disk drives though... Ones like these:
image from tpsoft.com
Ours were not quite that big... 5-platter disks with a capacity of 80Mb... An in those days that was a serious amount of storage
They enjoyed an amazingly fast data transfer rate on their parallel busses. Indeed when they could no longer be supported and had to be replaced by an emulator no current hard disk was fast enough... The emulator was thus formed from fast RAM with a background read/write to a SCSI hard disk...
That was in the days when I loved computers and their peripherals, especially the high-speed line printers I used to maintain...
My late father-in-law was a project leader for the original computerisation of DVLC. They were under strict instructions to be careful how the data was inputted so as to minimize the platter movement and not wear out the heads. Apart from when the Queen visited for the grand opening - when all bets were off and the drives were seen to be clattering merrily away to show everyone was busy
bobins wrote: 31 Jan 2021, 18:05
My late father-in-law was a project leader for the original computerisation of DVLC. They were under strict instructions to be careful how the data was inputted so as to minimize the platter movement and not wear out the heads. Apart from when the Queen visited for the grand opening - when all bets were off and the drives were seen to be clattering merrily away to show everyone was busy
Ahh, the heads... They were so delicate... We could tell by the smell in the computer room if one of the drives had suffered a head crash...
CitroJim wrote: 31 Jan 2021, 17:56
That was in the days when I loved computers and their peripherals,
I was HR and Pension head for a biggish company 15 years ago. Our computer operations manager was a really great guy, interesting and good at his job. He was ill one week and needed to sign some pension forms to meet a deadline so one of my team said she would drop round to his house. When she got back she said - "He's seriously odd ...". Fearing tales of misbehavior I said in what way. "He's got massive framed pictures of servers on his living room walls...."
Not called Jim though, so couldn't have been you. Each to their own.
Richard_C
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