Homebrew monitor - UK Vintage Radio Repair and Restoration Discussion Forum

Andy Doz · 5th Aug 2011, 11:46 pm

I posted some pictures of this up in the Pilot TV thread ... as it's loosely based on the pilot TV37, although with significantly different tube types!

Anyway... cut to the action....

PSU is up and running nicely, Line oscillator is , er, oscillating and the output stage is nearly complete. I've yet to sort out the EHT, but I've got about 650 volts, so that should be good enough for my CRT

http://i165.photobucket.com/albums/u...ell/photo1.jpg

http://i165.photobucket.com/albums/u...ell/photo2.jpg

http://i165.photobucket.com/albums/u...well/photo.jpg

http://i165.photobucket.com/albums/u...ell/photo3.jpg

oldticktock · 6th Aug 2011, 11:34 am

Hi Andy,

Fantastic, thanks for posting this thread and the pictures, truly enthralling and something I seriously would like to have a go at. Maybe when I have more experience under my belt I will.

I look forward to many more of your instalments.

Do you have more detailed info on the construction prior to where you are now? your thought processes, the valve line-up, schematic or are you working and designing as you go?

This is something we rarely see on the forum, a TV being shown built from scratch, from start to finish in the true spirit of the 1950's home-brewers.

Chris

Andy Doz · 6th Aug 2011, 6:48 pm

Not much further to go really... it's very much a bodge it along as it goes sort of affair..
I'm not one to spend hours simulating a circuit on a computer before I build it. I'd rather build it & tune for maximum smoke

Sorted out the frame oscillator this afternoon and mounted the crt.
Picked up a small mains transformer which I hope to use as an audio output transformer, if it doesn't saturate.

The EHT was woefully low, so I've sorted that.

Hopefully later on this evening I should have "first light"

Tube line up is ECH82 , 2x ecc90 , 8 x 6n1p, ecl83 , ez80 and ez81

6n1p's because I purchased a large quantity for peanuts, so they're expendable

Andy Doz · 6th Aug 2011, 8:46 pm

http://i165.photobucket.com/albums/u...P8060028-1.jpg

Andy Doz · 7th Aug 2011, 11:25 am

The small mains transformer didn't saturate! So I have audio
And I now have a small and unbalanced (but at least linear) raster... Despite having quite a large video waveform, don't seem to have much in the way of modulation.

Andy Doz · 7th Aug 2011, 11:26 am

It's funny how typing that out have jogged a brain cell. I *think* I now know why I don't have much modulation. Grid leak.

murphyv310 · 7th Aug 2011, 5:59 pm

Hi Andy.
What tube are you using? I like the chassis and the finish again what is it?
I started a VCR97 loosely based on the premier kit but when I was made redundant lost heart, I will definitely go back to it though.
I like your work, well done.

Andy Doz · 7th Aug 2011, 7:54 pm

Hi Trevor,

It's a DG7-32

"First light" can now be seen here : http://www.youtube.com/watch?v=5LBMcZ6dNC4

I'm chuffed with how good the audio amp is considering the output transformer is a 9V 240V mains transformer backwards.

The chassis is two die-cast boxes, side by side. Scavenged from scrap equipment from work. I have a few of them... all have holes in the wrong places

murphyv310 · 7th Aug 2011, 8:30 pm

Excellent!
Guess where I am going tomorrow! The loft!

oldticktock · 7th Aug 2011, 9:12 pm

Brilliant!

Ahh! and no better sound to have emminating from your work, the Doctor would be proud

Looking forward to further updates, looks like you've kicked started Trev's interest too, so we may have two projects to follow.

Chris

brianc · 8th Aug 2011, 1:30 pm

I love the use of pipe brackets for the CRT - Brilliant. The monitor looks superb. Great work.

5th Aug 2011, 11:46 pm	#1
Andy Doz Hexode Join Date: Feb 2011 Location: Gloucestershire, UK. Posts: 376	Homebrew monitor I posted some pictures of this up in the Pilot TV thread ... as it's loosely based on the pilot TV37, although with significantly different tube types! Anyway... cut to the action.... PSU is up and running nicely, Line oscillator is , er, oscillating and the output stage is nearly complete. I've yet to sort out the EHT, but I've got about 650 volts, so that should be good enough for my CRT http://i165.photobucket.com/albums/u...ell/photo1.jpg http://i165.photobucket.com/albums/u...ell/photo2.jpg http://i165.photobucket.com/albums/u...well/photo.jpg http://i165.photobucket.com/albums/u...ell/photo3.jpg

6th Aug 2011, 11:34 am	#2
oldticktock Retired Dormant Member Join Date: Nov 2009 Location: Weardale, UK. Posts: 1,981	Re: Homebrew monitor Hi Andy, Fantastic, thanks for posting this thread and the pictures, truly enthralling and something I seriously would like to have a go at. Maybe when I have more experience under my belt I will. I look forward to many more of your instalments. Do you have more detailed info on the construction prior to where you are now? your thought processes, the valve line-up, schematic or are you working and designing as you go? This is something we rarely see on the forum, a TV being shown built from scratch, from start to finish in the true spirit of the 1950's home-brewers. Chris Last edited by oldticktock; 6th Aug 2011 at 11:42 am.

6th Aug 2011, 6:48 pm	#3
Andy Doz Hexode Join Date: Feb 2011 Location: Gloucestershire, UK. Posts: 376	Re: Homebrew monitor Not much further to go really... it's very much a bodge it along as it goes sort of affair.. I'm not one to spend hours simulating a circuit on a computer before I build it. I'd rather build it & tune for maximum smoke Sorted out the frame oscillator this afternoon and mounted the crt. Picked up a small mains transformer which I hope to use as an audio output transformer, if it doesn't saturate. The EHT was woefully low, so I've sorted that. Hopefully later on this evening I should have "first light" Tube line up is ECH82 , 2x ecc90 , 8 x 6n1p, ecl83 , ez80 and ez81 6n1p's because I purchased a large quantity for peanuts, so they're expendable Last edited by Andy Doz; 6th Aug 2011 at 6:55 pm.

6th Aug 2011, 8:46 pm	#4
Andy Doz Hexode Join Date: Feb 2011 Location: Gloucestershire, UK. Posts: 376	Re: Homebrew monitor http://i165.photobucket.com/albums/u...P8060028-1.jpg

7th Aug 2011, 11:25 am	#5
Andy Doz Hexode Join Date: Feb 2011 Location: Gloucestershire, UK. Posts: 376	Re: Homebrew monitor The small mains transformer didn't saturate! So I have audio And I now have a small and unbalanced (but at least linear) raster... Despite having quite a large video waveform, don't seem to have much in the way of modulation.

7th Aug 2011, 11:26 am	#6
Andy Doz Hexode Join Date: Feb 2011 Location: Gloucestershire, UK. Posts: 376	Re: Homebrew monitor It's funny how typing that out have jogged a brain cell. I think I now know why I don't have much modulation. Grid leak.

7th Aug 2011, 5:59 pm	#7
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Homebrew monitor Hi Andy. What tube are you using? I like the chassis and the finish again what is it? I started a VCR97 loosely based on the premier kit but when I was made redundant lost heart, I will definitely go back to it though. I like your work, well done. __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

7th Aug 2011, 7:54 pm	#8
Andy Doz Hexode Join Date: Feb 2011 Location: Gloucestershire, UK. Posts: 376	Re: Homebrew monitor Hi Trevor, It's a DG7-32 "First light" can now be seen here : http://www.youtube.com/watch?v=5LBMcZ6dNC4 I'm chuffed with how good the audio amp is considering the output transformer is a 9V 240V mains transformer backwards. The chassis is two die-cast boxes, side by side. Scavenged from scrap equipment from work. I have a few of them... all have holes in the wrong places

7th Aug 2011, 8:30 pm	#9
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Homebrew monitor Excellent! Guess where I am going tomorrow! The loft! __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

7th Aug 2011, 9:12 pm	#10
oldticktock Retired Dormant Member Join Date: Nov 2009 Location: Weardale, UK. Posts: 1,981	Re: Homebrew monitor Brilliant! Ahh! and no better sound to have emminating from your work, the Doctor would be proud Looking forward to further updates, looks like you've kicked started Trev's interest too, so we may have two projects to follow. Chris

8th Aug 2011, 1:30 pm	#11
brianc Rest in Peace Join Date: Jun 2004 Location: Burghfield, Reading, Berkshire, UK, Posts: 1,055	Re: Homebrew monitor I love the use of pipe brackets for the CRT - Brilliant. The monitor looks superb. Great work.