Trough Line News.

Thanks Mike for your reply. Sorry I should have said U H F rather than VHF regarding signal loss.

Radio 3 on here at the moment and its sounding fantastic.  

Just been listening the Radio Three Relay. Wonderful. 

The Trough Line is wonderful with the proviso that the signal is incredibly small into the unit. It is a rotten area for easy FM/VHF reception, but clearly the tuner is capable of better quieting with a stronger input from a more efficient aerial. I have shown that already ... at a previous house.

In a post-Lottery-win World, of course I’d get a nice cottage on top of hill with good reception from Sutton Coldfield!

Actually delete that, the residence would also require to be near a good bus stop! With an acre or two of ground to grow birch to burn on the fire. And go off grid apart from Solar and an AC regenerator to give me enough power each evening for decent music replay ...

Dreams are pointless if they could easily be achieved!

ATB from George

PS: Another solution would be to get a tuner that required a less substantial signal from the aerial! But the easy route is not always the best of most satisfying!

Hi George,

You where right radio 3 last night was stunning.

Regarding the low input sensitivity of the Troughlines are there signal booster's for VHF available ?

This might be worth investigating in the future to quieten things down more.

Like your post lottery picture on how things will be.Very down to earth and no talk of Statement in sight.I could see the garage with a few more vintage bikes in it though.

Have a good day Ian

Indeed, at VHF frequencies I would concentrate on the quality of the cable jacket and the external connections.. Cracking through UV and water ingress will make the losses of any cable significant. Also check the quality and fixings of the BalUn.

For premium low loss cable at higher frequencies, then it has to be Hardline. Working with it makes NACA5 look like a walk in the park... it has a corrugated solid copper sheath and solid copper core .. and it is typically used on mobile phone masts... but losses over extended lengths are truly minimal.

For domestic use I would only recommend if you had a radio antenna 50m or so away from your radio receiver... and perhaps were needing to do direct cable burial.

Simon

Dear Simon,

I am just waiting for the Antiference aerial to come, and I may well post here and pick yours and Mike’s brains further!

Dear Ian,

It is funny, but the greatest pleasure I can think of in life would be sitting in a quite small living room with a wood burner in one corner and an open fire in the hearth on a bitterly cold dark winter night. The ideal would be to be the owner! 

I hate central heating. Daft idea. Just heat the room you are in and if you have a wood burner then you can have a hot water tank in the bathroom which takes the edge off the cold in there! 

As for my replay, I would not change it for any amount of money. It brings me un-alloyed joy. It brings me fun with jigging about with things like my old radio. It would be very easy to buy a uber-expensive  [and indeed rest of the system] radio and just plug and play. What would be the fun in that?

The Trough Line may be the harder route to reliability, but in sonic terms it is superb. Rather like the last six or seven years getting the Carlton exactly into the condition I want her ... Of course I might permit myself a third cycle, possibly newly made and bespoke, with a Rohloff gear and traditional steel frame, with a really nice set of running gear. Strangely though, neither the Carlton or the Raleigh leaving really wishing they were different or better.

I would not run a internal combustion engined car, but build up a Renault 4 with electric motorisation to be charged on Solar only. If the charge was insufficient from the Solar, then I’d refrain from using it. The great thing about the Renault 4 is that is so light for its accommodation, so a quite restrained electric motor is all that would be needed, and yet the car offers a lot of space for the batteries, so with additional battery units, the range could be made very large indeed for my very rare long journeys. The last car I owned [if ever so briefly] was a Nissan Micra, and even in that I could get nearer six than fifty miles per gallon, so I imagine my driving style would suit a low powered electric car. 

ATB from George

Hi George nice comments about your lottery plans.Cosiness and contentment sums it up well.

With regard to a possible third bike in the plans,I can think of no better British bespoke frame builder than Mercian Cycles in Derby.Check out their website,you will love it.There is even a bike that Paul Smith the fashion designer who has always been mad about cycling designed.Mercian mainly work with steel and absolutely no carbon in sight !

With regard to the Troughlines low output can One Thing do anything to boost it ?

One thing you will have to do if you ever did get lottoed would be to have the Graham Tricker mods on the Troughline.That would round things off nicely.

Hi George.. Your interest in valves and audio prompted me to have a play. I have bought a budget valve headphone amp for my GR10's.. a Little Dot  mkiii .. I'll let you know how I get on.. Plan to use with my Naim NAC and portable audio equipment.

Simon

Dear Ian,

If you feed the relatively small output of the Trough Line to a highly sensitive valve amplifier input then you get the volume back, within the limit of the possibility of the amp to drive the speaker. 

With the limited possibility to accept much power, but good efficiency, you can have room filling music, but not stomach churning bass with a speaker like the ESL.

At the time of the Trough Line the Leak pre-amps always reduced the tuner input to the power amp, though it magnified the microphone or gramophone cartridge input!

A simple modern passive pre-amp would allow the valve power amp to either be fed un-attenuated [for the Trough Line] or cut back for modern 2 volt Line level devices like the DAC V1, for one example. 

I think a well balanced vintage system for radio will be fully assembled by Easter!

Dear Simon,

Valve amps are almost never very powerful but can be [at their best] suffering low distortion even at full output, but the old saying is that ten Valve Watts are worth fifty Solid State, because valves clip gently, and the amps themselves are robust when facing an unreasonable input power. Okay that the result will not sound well because of soft clipping, but the amp will survive and so will the speaker as a DC failure will not pass the output transformer. On the other hand it is crucial that a load is connected to the amp if it is turned on or else the transformer may be ruined ...

Very different from Solid State, valve amps have good and bad points. But the best of them are far from what people think of valves. Soft, slow and in-articulate, and particularly lack clear bass. But they are not suited to AC/DC and their ilk. Their strengths [in the best designs] are similar to those of the ESL. Articulate, precise as to timbre and pitch [and in the best example particularly so across all audible frequencies], and euphonious under pressure. No harm in being euphonious under pressure! Though not necessarily forgiving of poor recordings or relays as compression is ruthlessly revealed dynamically, and as is a hardening of timbre with bass compression.

I guess that valves would have little interest to those who value shear volume of sound punch over subtlety!

I am now getting impatient for getting a more efficient aerial than my loop!

ATB from George

Dear Gents, if someone would go back to glass tubes then I have somewhere a good schematic of an headphones amplifier that have not output transformer as is capacitive coupled. I have also realised it in my formal time and the prototype should still be somewhere in the roof of my father.

At that time it has sounded good with high headphones load (since then I still use time by time a BayernDynamic DT811).

Aha! The aerial is huge! A good six foot long! 

I have it connected to the balanced inputs on the Trough Line one side to one of the dipole pair and the other, the other, with the aerial mounted on a tall music stand. 

Totally ghash!  But the signal is glorious! No question of this being marginal.

When I can find a way of supporting the aerial nearer the ceiling then it will be even better because it will not be a nuisance! But - apart from its sheer size, which I’ll get used to - this is very pleasing, and yet so far only the beginning of the experiments with connections and precise placement, though the particular placement seems to make almost no difference providing the aerial is pointing in the right direction. Interesting that this completely rejects Sutton Coldfield when pointing at Ridge Hill. I cannot point it at Sutton in the room in any case.

Good concert from Bournemouth this evening!

ATB from George

Aha! The aerial is huge! A good six foot long!    

I'm surprised you are surprised George,  but yes they can be a bit of a shock when you get up close.   You should see my Ron Smith Galaxy in a room,  yours is more or less flat in the vertical direction,  a Galaxy is .... er ....  lets say 3 dimensional

Your dipole width is dependant on the antenna's tuned frequency so will be more or less the same no matter the make or element number.  The 2052mm length is of course a product of the required element spacing formula & the number of directors.

I expect reception will be even better when you use coax on the 75 ohm connections,  the Antiference "Trumatch" dipole is one of the few dipole designs that has near 75 ohm across all its frequency range.  (It does not need a balun)

Anyhow,  have fun & keep posting

Yes they always look better on a chimney .

My SW Yagi is 11 metres or about 35 feet across.. Always looks more 'discrete' on top of its tower 

Mike, a BalUn is not about impedance matching.. Although you can wind it to act as a transformer if you need to, its primary function is to convert a balanced antenna to be connected to unbalanced feed such as coax. (Hence the name)

Dipoles and Yagis are balanced antennas and so do need a BalUn to work optimally with coax.. Otherwise the shield of your coax becomes part of the antenna.. The impedance will go umatched and the performance, pattern and gain will deteriorate big time.. along with possible pick up of interference and noise from the coax...  it's good old physics..

Simon

Dear Mike,

No more experiments today. It is lovely even in un-refined set-up.

I have seen a Galaxy aerial up close, and to be fair, I could neither get away with one on the roof nor inside! 

Inside is a compromise, though the connecting lead is then very short. As I do not own the place, if I can get it superb inside then I am not going to try experiments on the roof. It is already fine enough, so further refinement will be about preserving [or improving if possible] the quality, but mostly about minimising the impact of what is hardly to be called an inside aerial!

I shall permanently modify my old music stand as it is very strong, to mount the aerial, so at least it will have continued use. I cannot bring myself to throw good things away, though I do give them away instead!

I tried to give the Trough Lines away, and they came back three years down the line. I think that is called Karma, or something of the sort!

ATB from George

Dear Simon,

Can I use “ladder line" to connect for a run inside of only about six feet, and would this be likely better or worse than some Coax? If potentially better I might spring for a length as indicated on the thread you started some weeks ago.

I have some coax, and of course I also have the BalUn from the initial experiments with my loop.

The stronger signal has brought no change in timbre, but more detail, and quieter back ground.

Best wishes from George

The direct relay of the Bournemouth Symphony Orchestra concert of Beethoven’s Fourth Piano Concerto and Elgar’s Second Symphony was absolutely superb. The Symphony was given a performance to rival Elgar’s own recording on HMV from 1927. Twelve 78 sides recorded in one day. They worked fast in those days! If anyone had heard the Trough Line revealing the inner workings of this music, fast and furious and then reflective, no suggestion of smooth valve sound would come to mind. Indeed just as ESLs make all other speakers sound ponderous, so these old valves made solid state sound stately and just a little aloof of the vitality!

Tomorrow evening I’ll listen to this again on the Radio Three iPlayer!

ATB from George

Simon,   I am fully aware of how dipoles & unbalanced feeds work.  In my early years I installed & serviced SW, ship/shore & navigation radio & sometimes that included experimenting with balun's.   It was all transmitting & yes I agree that is were a balun does everything you say.  However with receiving FM band my last experiments were a couple of years ago with my G-14 where we exchanged some posts - I finally concluded,  together with a signal strength meter,  that a G-14 was not best served with a balun.  

Antiference has deliberately chosen to not include a balun in its unique FM open dipole design or their basic open dipole TV aerials, but they do include a balun with the folded dipole TV aerials;  it seems they might have tested & weighed up the pros & cons with each design & have disregarded balun in the open dipole applications.

The use of BalUns or not is very standard and staple examination stuff in RF engineering and radio licence operation as I am sure you aware ... It certainly can cause a lot of issues with novices not using BalUns when connecting balanced antennas to unbalanced leads..clearly you don't have to use a BalUn but you are compromising the performance of the antenna no matter what the marketing dept say of the anteenna.. and historically some antenna manufacturers have been renown for outlandish statements.. and only relatively recently with computer modelling could they be effectively proved or disproved.. Their powers don't usually extend to rewriting our understandings of physics.. Of course if the impedances match, most riggers worth their salt will create a BalUn by looping the coax six or more times at the antenna feedpoint.. This can be very effective.. and is extremely low loss. In fact this is exactly what I do with my DAB rooftop Yagi.

George, you can use balanced feed to your antenna, just connect each wire to each side of the dipole element. The impedance a might not match, but should work effectively for receive, and importantly he gain pattern and front to back rejection ratio should be optimal. 

Simin

Hi George,

Sounds like you are getting closer with the ariel work.I don't know how much better it would be on the roof,but if you are happy with the indoor setup thats all that matters.Maybe less reflection if it was on the roof ?

Happy listening

ATB Ian

The first connection was rather good - between the two halves of the dipole and the 300 ohm balanced tuner inputs, ... which was quiet compared to noisier on the 75 ohm inputs, and made of a mains lead with the plugs cut off!  ... unfortunately too short for comfort as it required the tuner to be in a strange place in the middle of the room! It worked superbly, and was so effective in the quietude that the difference between the MAC Mini being on or off was possible to discern. This is the first time I have ever noted that the MAC can have an effect - presumably on the mains from its power supply, which is of the Switch Mode type?

On the way home I brought 3 metres of two core, and to be honest this is not good! It woks but the noise is unacceptable. Later I’ll get the coax out, but cutting the ends down on this requires patience!

Last evening’s concert from Bournemouth was just about the best radio replay I have ever heard, so getting it just so is in sight and must be possible.

I enjoy the phase of experimenting, but once it is fixed, I am more than happy to sit back and enjoy the results. 

First supper and then coax! Hopefully in time for the concert from Liverpool later on ...

ATB from George

Not you as well, George! So jarring to a Brit-English speaker. An "English lecturer" did the same from Brussels on PM, earlier this week. Maybe you, like him, have gone all trans-Atlantic ;-)

Please consider an outside aerial.

Best,

Chris

Dear Chris,

I was the despair of my English teacher. He thought that I was deliberately making mistakes to irritate him, which was quite wrong of course.

I would have welcomed then as I still do the pointing out my errors. I actually thought about that before I did it! I was not sure - could not remember - which way is correct!

Anyway, though the big aerial is hardly a thing of beauty it is getting excellent results inside, so I really cannot countenance the cost of getting a pole and drilling holes through several walls three bricks thick, and not least getting permission from my landlord and the management committee! If I owned the house it would be different.

I have just put on the coax. It is strange that the MAC upsets the tuner. Could be mains or it could be radio interference. In any case, I don’t usually post when music is going, so it is not a big problem. 

No doubt the tuner comes from a time when Switch  Mode Power Supplies were un-thought of! 

With these disconnected the reception is wonderful, so I’ll sign off for today, and see what I might think of tomorrow, such as a BalUn!

ATB from George

Quickly, during the interval. The coax with the braid on the earth terminal and the signal line on the 75 ohm unbalanced input was quite inferior. I have just broken every rule and fitted the braid to the balanced 300 ohm input and it is not quite as good as the short plain two core on the same inputs though better than the long two core connection. The signal has significantly diminish using un-balanced 75 ohm. Shown by the magic eye and overall quality.

At this point I am going to stop for a while, and get some ladder line and try that on the balanced inputs. 

No doubt that a correct impedance transmission line will stand every chance of being better than two core cable! On the balanced inputs the Trough Line is almost immune to the MAC and both are on as I type.

When I get this as fine as possible, then I will try reverting to my loop! 

Experimentation is about finding out, and then validating.

Anyway, Mozart’s Haffner Symphony is on in few minutes, so I’ll sign off till tomorrow!

Best wishes from George

What about one to the roof?!    ;-)

Best,

C.

edit: Yes, I know you heard me the first time!

Dear Chris,

The gutter is 45 foot up! And the pitch is rather steep in the way that very early nineteenth century builds can be. Not easily done by me, and not cheap for an installer.

Essentially I cannot afford to pay someone to do what I cannot!

Best wishes from George

George, interesting regarding your Mac. What you are hearing is almost certainly the RFI from your Mac. Many valve designs are far more sensitive or obviously affected by RFI than their semiconductor cousins. You might find a GSM phone in the room causes interference on the radio when registering with the base station.

i can certainly hear the RFI from my iPad on my latest valve amp when it is within two to three freet of the valve amp. I guess I would have to fully shield my valve amp in some sort Faraday cage to stop this.. and my valves are exposed. On the other hand valve equipment can show you how electrically noisy much modern electronics are... and of course this RFI is what some can hear on sensitive modern semiconductor audio equipment.

Simon