I would definitely be interested in one Ian. But I have to get my HMV F3 A2 to you first to check the chassis and tube. I will get it up there to you soon hopefully.

I'm back at work on the 15th so the sooner the better will work for me, anyway.

I've been testing the box on a variety of content and it looks like I may have been unnecessarily aggressive with the white clip setting. It tends to invert the peak whites to light grey (like a low-emission CRT) and the effect is not pleasant to watch. It's generally OK on film-derived content but videotaped content often pushes the white peak level already to make the image more "vibrant". Example: a white shirt in daylight turns to chrome!

But the clipper certainly removes the sound buzz.

Anyway I will either make the white clip switchable or adjustable I think.

So far I have assembled 5 boards out of the 10 prototype PCBs I had made, 4 of which are in plastic cases. For anyone who's willing to tackle a SMD PCB with some patches (lifting some pins on a couple of chips and hand-wiring them) the 5 leftover Version 0 PCBs are free to a good home!

HMV !
I know where there is a nice HMV , first wave 57 -58.
I was going to buy it,but I have some good tellies at the moment and some work and some dont so I didnt want other project in waiting until I get the others finished ,,so I gave it a skip....
The first wave HMV TVs are very nice with knobs through the screen.

Pete

2nd wave actually Pete. 21 inch 90 degree F series. There was the E series (17 inch 70 degree) prior to that, I think HMV at the time would have liked to have forgotten them!

The F series was certainly a textbook design, complete with 4 stages of VIF and RCA synchrolock (RCA themselves had abandoned this circuit by the early 50s, it was too complicated and expensive).

Some F series models had PP audio amps using a pair of 6BM8s.

The vertical was interesting too, current feedback and no vertical linearity control needed.

Complex TVs that were capable of excellent performance. Pain in the neck to work on though.

Would anybody on the forum know anyone who has a spare Masonite back that they would be willing to part with for my HMV F3 A2.?
I suspect finding one might be difficult but I will need it.
The bottom piece is there behind the speaker but not the top.

Ian, I am hoping my HMV is not to much of a pain in the neck to work on!!

Tall order that one!
I have low boy parts ,but thats no good to you.
You might be best to track down a complete unit, that way you have spare crt and FB if the dreaded day ever came.
This is why I keep buying vintage TVs , its not because I want too restore them, but crts, knobs, backs, cloth, fb, are now impossible to find and so the hobby dies if I cant get the stuff.
Making a back would be easy too,

Pete

Thanks Pete

I have come across a couple of units on auction sites over the last few months.
It's a good point you make that another TV might be useful for parts.
I will keep on looking and see what turns up.

OK! It wasn't the clipper causing the problem (I found that hard to believe from the scope anyway) but the modulator.

Biassing the subcarrier input up by about 0.4 volts by putting 100k in parallel with R28 fixes it. It's a bit critical, that voltage, a small change makes a big difference. It's probably that critical because I'm being strict with the front porch clamping, the circuit in the datasheet lets it float around a bit. So I'll try the other 4 boards with the 100k added and if they are all good I won't add a pot to the design. (I always try to avoid pots).

It has much better DC restoration than any other modulator I've used. It looks particularly nice on my Kriesler 79-2, dark scenes actually go dark like they should. And despite the fact that I haven't yet got around to freeing the slugs in the ratio detector, there's hardly any buzz in the sound and you can actually listen to it, unlike with the Kingray modulator.

I'm happy now!

Hi Ian,

Like Pete, I'd love one of these but I'm sure that I would not have the confidence or expertise to construct one. Would you have a spare one still available now that you've made improvements to the design?

I'm currently restoring my two Healing 701 sets (a Capitol and a Waldorf) from1964/5 and will need something to successfully enable viewing of DVD's etc.

You can see pictures of my two Healing 701's on a previous post of mine.

Regards,

Barry.

Yes Barry, drop me an email and join the queue!!

I'll assemble some more I think! I've had 4 of them running for a few days now and I'm happy they are stable.

I should point out that the modulator is not crystal locked, but then neither is your TV and this device is far more stable than the average valve tuner.. Crystal locking is possible but adds too much cost - custom crystals are hard to source and expensive. A PLL is an alternative method but where do you stop?

Thanks Ian,

I'll email you directly.

Regards,

Barry.

MY MODULATOR !
well, I went around to see my friend Ian to chat about vintage tellies and pick up my modulator.
The workmanship and quality of these units Ian has built is amazing.
The images it produces on vintage TVs was simply great.
No white lines anymore! Good clean images with all the right tones and nice clear sound.
Now someone like me who loves and collects vintage TVs, this device is wonderful, because as you know even after we restore our sets sometimes these white lines and sound and other issues still persist because of modern contents being displayed on a 60 year old system.
Well this unit Ian has designed and built displayed the images and sound how it would of looked originally.
For me this is important as I have many vintage televisions and I get great enjoyment out of watching them.
Thanks Ian!

Pete

Great outcome.

How about some video from one of you? Maybe via a YouTube clip -- but mind the copyright police.

Yes it is Great G,
Particularly regarding white lines that appear on vintage sets,
Its frustrating because you know theres nothing wrong with the set. Out of all the modern content issues that some vintage TVs get ,Its the white lines that are driving me too the nut house.
Im not sure why, not all sets get the white lines ,but the old sets will all get some of the modern content problems either being in the sound or the grey scale or the lines.
But I know nothing about electronics so I dont know why its that way.
The grey tones in bw is extremely important for viewing movies and in filming or photography its measured with a 18 percent grey card to insure the hilights and midtones will have detail to some degree in all .
But that all seems lost when playing some modren dvds on some old tellies.

Ill see if I can make a vid,

Pete

Pete

Somewhere in a drawer I have a "Macrovision Defeating Set". I think I bought the thing at JB HiFi back around 2001. It's basically a box the size of a VHS tape with RCA IN/OUTS and a DC input from a power block. If I can find the thing I'll put a picture of it up for you to look at. The reason I bought the thing was that my DVD player at the time was throwing out this awful herringbone interference on my old Sanyo CRT set. It didn't do the job and I never got around to returning it. The herringbone pattern was something to do with the power, I think, because when I had my external fusebox (with the old type ceramic fuses) moved indoors and replaced with breakers the interference went away. Oh...and why did I put the fuse box inside? Because rotten burglars cut my power while I was away and waited a week or so for the alarm backup battery to die before trying to burgle the house. Unfortunately for them a neighbour spotted them and they had a free ride in a divvy van.