Golborne Vintage Radio

Hi.
Wonderful results.
I need to get another Hedghog and would want it to support both conversion standards. Failing near vision warrants me to buy a completed unit. Where and who do I contact?

Stephen Evans (Freya) was offering assembled Hedghogs. I can give you his contact details.

Brilliant Jeffrey.
Thanks

Frank has taken the interesting approach of overclocking the TVP5150 decoder chip. I'm doing underclocking of the SAA7118 in my design but when Frank tried this on his, there was too much jitter on the decoder output. I've no idea if overclocking would work on the SAA7118 in my design but I've no real need to try.

Underclocking if it worked well enough would have been the best way. To get overclocking to work I had to turn off everything except the ADC. The analogue AGC had to be disabled as it would slowly keep increasing the gain until the picture was whited out. The Video input level are more critical on 405 to 625 because the AGC being disabled but they still have a reasonable range.

Frank

I am new to this forum. so first of all Hello. Frank kindly sent me a Hedgehog circuit board and I eventually got it working. I have been reading with interest this topic and to me Frank is a master
I do not know why would you want a 405-625line converter?
It would be interesting seeing the output quality of two Hedgehogs going from 625-405-625 line.!
Could the Hedgehog be modified to produce the system used on BBC TV launch night, Bairds 240 line 25 f/s system?

The Hedghog can't do Baird 240/25 as it doesn't have a framestore. Similarly the Aurora SCRF can't do it.

I developed the original ideas for 405 to 625 conversion to make it simpler to recover archives of 405 tapes. These will normally be 2" quadruplex or Sony CV2000. The other application was if the broadcast Engineering Conservation Group wanted to originate pictures on 405 for project Vivat.

Hi television1936.
Well done on getting your Hedghog working.
Jeffrey has answered your question about 240 lines.
As to why I need a 405 to 625 line converter. Well I don't, I have no real use for it.
But as it is 'free' only needing a firmware change why not  
Maybe someone might want to backup some material rerecorded on 405 lines.

I have attached two photos below. They don't do justice to either the source or output.
They are of Test card C on Mike's Test card CD.
The first is of the CD player connected directly to the monitor.
The second is the same test card after been converted to 405 lines and then back to 625 lines. Which is displayed on the same monitor.

Frank

That result is amazing.
Just goes to show you how good the horizontal resolution was on 405. To convert to 405 & back to 625 and give the results is truly amazing.

That is seriously impressive!

Peter