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Leak TL which decoder?

Arkless Electronics said:
Some of the TOTR USA FM tuners were very good indeed but they were vastly more complicated and vastly more expensive than the crude Troughline.
There is no actual point in a valve FM tuner beyond nostalgia of course... but in this thread where those asking the questions would not know what a mixer is... or an intermediate frequency amplifier... further discussion is as pointless as trying to discuss cars with people who don't know why four is the normal quantity of wheels and round the normal shape!
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For those who want to do an amusing experiment...
Take a Trough Line and another tuner next to it and be amused to be able to change the other tuner's stations with the Leak and note the 12 Mhz (not 10.7) difference on dials!
This little experiment actually checks the presence of IF quick and dirty. Then grab the frequency counter and the scope...
 
Oh dear. I’ve just caught up with the thread again. It got very volatile.

I’ve still got my TL in the background whilst fettling in my workshop. Very comforting it is too.

I’ve very recently updated the DAC in my listening room and, coupled with a Bluesound Node 2, it’s producing some superb internet radio. That’s thrown another cat in the pigeons scenario.

I have come to one solid conclusion though. I’ve spent months/years mucking about tweaking and changing units. In the end though. Does it really matter what you listen on? When you get to a reasonable level the music sounds good. Not as good as being there but good enough to allow one to enjoy it. Instead, I think, a lot of people get hung up on listening to their system and completely loose the enjoyment of the music!

I suppose that is the marketing man’s dream on a Friday afternoon
 
I have just stumbled across the thread and the strong feelings piqued my interest because I have one of Tim De Paravicini's blue boxes that was built by himself. In addition, somewhere in the attic there is a Troughline Stereo Tuner that Tim modified for use with his decoder!! Give me a day or 2 to search and will try to put the two pieces together and have a good listen. It will not settle any disputes but I can compare the results with a NAT 01!!

FF
 
I put it all together and had a long listen both in a Naim system and also via STAX SR 404 Signatures. The sound quality is truly excellent but the criticism is that co channel interference is poor. I need to set up a better aerial but the results are very encouraging. Tim de P certainly made a truly excellent decoder and the Troughline is a good source to go with it. Is it a NAT 01? - I don't know as I need to put it on the STAX set for a while and use the aerial that the Troughline used. BTW the aerial was a George Johnson invention!!
 
FrancisClement said:
... BTW the aerial was a George Johnson invention!!
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Goodness that takes me back! I made several variants of aerials for VHF-FM in the old days.

I did not invent them! But I did make two types based on 75 and 300 ohm designs - a copper pipe di-pole and a copper pipe formed into a circle with a tiny gap connected to 300 ohm ladder line to connect to my then Trough-Line Two. I cannot remember the precise dimensions now, but I looked up the references in print in reference books [remember those!] and especially the 300 ohm ring worked superbly. It was scaled to tune best at 93 M/cs for Radio Three [from the Ridge Hill mast, Much Marcle, Herefordshire]. I remember it was about 1012 mm in diameter.

Nowadays I have a simple 75 ohm wire di-pole. After much experimentation, I lengthened the di-pole arms again to optimise for 92.7 M/cs for Radio Three from the very powerful Sutton Coldfield mast. For a while I ran this horizontally, which brings a small degree of directionality to the reception. One day I turned it vertical, having discovered that Sutton sends in both vertical and horizontal polarity. The advantage of a vertical aerial is that it is much less obtrusive and works just as well. I have mine suspended from a hook, and it has a small wooden block attached at the bottom which keeps it absolutely plum. It also returns to where it should be if disturbed. Being thin wire it has now completely de-kinked after a couple of years.

I have the di-pole on an east-facing wall catching Sutton Coldfield at a bearing of approximately 047 degrees [ie. north-east], though this is no longer relevant using the aerial vertically.

I use this old tuner daily. It will be sixty-four years old in a few months!

I love reading threads like this. Thanks to everyone posting here.

Best wishes from George
 
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I have set up the aerial properly with 26 km line of sight to the radio mast. The tuner needs to be allowed to warm up of course and then the fluorescent bands on the strength meter almost touch in local mode. The results are really pleasing with excellent sound quality and no hash and the tuner rejects the stations close to the intended signal properly.

OK I am in Spain but the Spanish Radia Classica gives some really excellent live music - classical, jazz, flamenco etc. Sound balance is excellent and stereo image is very good. So there you have it, a real bargain when you consider the £50 for the tuner and probably £300 for the EAR decoder. On top of that there seem to be no plans to remove FM in Spain. Do I sell the Troughline or the NAT 01????????

FF
 
FM Yagis seem to be almost extinct. My remaining one is about 14 years old and has been battered by storms from the sea a hundred yards away in all that time. Some of the elements are waggling about in the wind now, so I bought an Antiference 5 element replacement on Amazon. Just need to get it fitted next as my days of going up on the roof are over I think.


https://www.amazon.co.uk/dp/B00BDIVCGE/?tag=pinkfishmedia-21
 
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This site contains affiliate links for which pink fish media may be compensated.
Blimey! I am surprised. This thread is still running, seems to have calmed down a bit.
Well, I’m still listening to my TL and enjoying it, even with its original decoder (Mullard ?). I haven’t had the heart to sell it on and it is good. On R3 there is no evidence of sibilance, distortion or strange whispering in the background. Live concert recordings on my Studer are a real joy to listen to, repeatedly.
I still have the FM bug though. I’ve recently bought a Quad FM4 for a very reasonable sum, which is now sitting on a Quad workbench for servicing.

I still stand by my previous statement. Whatever kit we use to listen to FM we are very much in the hands of the engineers who control the broadcasting. Some of the BBC stuff (whatever their politics ) is truly outstanding. Compare that with other commercial channels where the output is absolute crap and not worth listening to (amazingly the adverts have strikingly good reproduction though, can’t think why?).

IMHO, I find that to sit and listen to a live concert through the TL takes some beating. Yes it may not suit the perfectionist audiophile but their’s tends to be a rather esoteric view. If anyone who has visited a concert at the RAH must be aware, the background noise in the quiet passages is anything but silent. The acoustics and air con see to that.

A sign of the times perhaps . . . my wife and two forty something sons usually stand looking into my listen room and shake there heads thinking he’s lost his marbles again . Do I care?
 
I haven't used an FM tuner for a long time now, having succumbed to internet radio and it's added convenience, but I do have a Leak Stereofetic in the cupboard under the stairs and a Denon up in the loft. I'm not sure that a roof aerial would last long where I live, but there is plenty of room up in the loft; any suggestions?
 
I don’t know the Denon but I also have a Stereofetic. I think if I were you and haven’t listened to FM for a while I’d get the Leak out from under the stairs and give it a listen, you may well be pleasantly surprised. You’d be surprised what signal you can get from a length of ‘doctored’ coax cable. There are a lot of descriptions for aerials on the internet. It won’t surpass a properly install yagi but it will give you some idea.
 
A bit late to join in (or is it?) but I have a TL with One Thing decoder. Sounds great, no real issues - slight odd sibilance on speech on R3 but all else absolutely fine and sounds very dynamic.

Andrew
 
No, it’s never too late.
Is your One Thing decoder an internal or external unit. Excuse my ignorance but I’m still learning.
 
I have a stereo Troughline with the original Leak solid state decoder. It's totally original apart from a three core mains lead and still works fine. I do realise that the Leak decoder is a pretty poor performer but I have a spare one that I was going modify. I bought a modern decoder on a small pcb but never found the time or the inclination to get on with the job. More recently I've been enjoying internet radio and I don't have the big aerial on the chimney any more either so unfortunately the Leak has taken a bit of a back seat. That's progress I suppose :(:)
 
Linnovice said:
No, it’s never too late.
Is your One Thing decoder an internal or external unit. Excuse my ignorance but I’m still learning.
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It's an external one, just a smallish box. I had a reasonable aerial but nothing special, and never had hiss problems. Moved house recently so it's all still packed away.
 
At some point in the new year I should have capacity to make decoders for Troughlines (or other vintage tuners).

The simple fact that they would be hand made to order means they will not be cheap.

John Linsley Hood did a lot of work designing the ultimate stereo decoder in the late 80's/early 90's and published his findings and circuitry in ETI magazine... it all got pretty complicated as I recall! There were various update articles where in effect he presented MkII and III versions as he came up with new ideas etc.

It should be viable to make these for a customer also. I've not heard one and don't know anyone who has but theoretically they should be as good as it gets.

As I've made clear up thread though I won't be using any of this myself as I find even a Stereofetic to thrash a Troughline and a cheap Denon tuner to be far better!
 
I’m curious. Quite often a Stereofetic is quoted as being superior to a Troughline Stereo by a substantial amount. Why? In what way?
I have both and quite agree that the ‘sound’ is different but I prefer the Troughline to sit a just listen to for long periods. I also have a Linn Kudos, Hitachi FT5500 MkII both of which offer good, though different, reception. All the SS units are different without any standing out as superior, just much of a muchness. I just wonder why the Troughline gets such bad press.
 
Linnovice said:
I’m curious. Quite often a Stereofetic is quoted as being superior to a Troughline Stereo by a substantial amount. Why? In what way?
I have both and quite agree that the ‘sound’ is different but I prefer the Troughline to sit a just listen to for long periods. I also have a Linn Kudos, Hitachi FT5500 MkII both of which offer good, though different, reception. All the SS units are different without any standing out as superior, just much of a muchness. I just wonder why the Troughline gets such bad press.
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Remember that Leak made the Stereofetic as a MUCH more modern superior replacement for the Troughline.

The Stereofetic was bleeding edge technology when it came out and one of the first FM tuners to use dual gate mosfets in the front end and also one of the first to use IC's (in the IF strip and stereo decoder).
It's nothing particularly magical or anything but is a competent FM tuner roughly similar in performance to yer generic decent tuner of the 70's and 80's. The later Leak Delta FM is pretty much identical internally but was restyled and built by Rank after they bought Leak. The Delta 75 receiver is worth a look at and combines uprated versions of the tuner and the Delta 70 amplifier in which, due to the mods, both the tuner and the amp are better than the separates by a decent margin. The 2000 series tuners are even better but avoid the 2000 amps and receivers like the plague as the amp sounds awful (in spite of being high tech for the time).

The Troughline Stereo, with it's own built in original decoder, was not even hi fi! It was a kludge to have a stereo compatible tuner for sale when the stereo broadcasts started. In this form they sound rather like a Medium Wave radio to me. There's bugger all treble, little stereo separation and they sound rather "like grans old radiogram".

The Troughline is great at what it was originally designed to be.... a MONO FM tuner, and works very well in this capacity. If you have a very well aligned one with good valves, a good external decoder AND you are lucky enough to live somewhere with a superb FM signal, ie both very strong indeed AND very low in reflections which cause multipath distortion, then they can sound fine.... but for most people in more typical reception areas they just don't cut the mustard in stereo... for very good technical reasons, unrelated to whether they are valve or SS, involving lack of sensitivity, poor capture ratio, poor IF group delay performance, inadequate IF bandwidth and borderline bandwidth in the Foster-Seeley detector which converts the 12MHz IF to audio. All these parameters were just fine for mono of course as that's what it was designed for!
 
Ok, yes. I do get that. I’ve just done a thorough A/B so can’t deny you are correct.Perhaps I’m getting lulled into a sense of security in these troubled times. A comforting listen to ‘gran’s old radiogram’ (or more like ‘crystal set’ in my case ;)) is no bad thing. I can’t help liking the magic eye though. :)
 
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