Ultra V1770 - my first telly and Im struggling

[Exiled Yorkshireman]

Thanks Jeffrey. Any idea how I'd get in touch with Stephen? There doesn't seem to be a PM facility here.

[Mike Watterson]

Click on the white envelope, left of search magnifier icon, below Location on a profile.

[Exiled Yorkshireman]

That'll teach me to a) use a small screened laptop and b) forget to clean my specs.
Ta muchly Mike.

[ppppenguin]

There are a couple of forum threads about the Hedghog:
https://golbornevintageradio.co.uk/forum...p?tid=6193
https://golbornevintageradio.co.uk/forum...p?tid=6799

These also contain references to making 405 signals by other means. Peter Scott and others have done good work generating 405 signals from a PC. I have also seen 625 to 405 conversion done with a Raspberry Pi. A separate modulator is needed with both these methods.

[Mike Watterson]

I think needs a Pi5. A Hedgehog seems like good solution as it has the modular and one from an old VCR is no use for 405.

[`FRANK.C]

I believe Stephen has also builds the Hedghog V which can store 6 images. Test card C or whatever you want.

Frank

[ppppenguin]

I think needs a Pi5. A Hedgehog seems like good solution as it has the modular and one from an old VCR is no use for 405.

I'm fairly sure the demo I saw was with a Pi 4.

[Exiled Yorkshireman]

I now have a Hedghog IV (thanks Freya). The project is on temporary hiatus while I deal with some cancer treatment. I'll post back when I restart.

[Exiled Yorkshireman]

So, in between the bladder biopsies and surgery for the prostate cancer, I've just had time to adjust the tuner. It was well out on all channels, but I've now got it more or less spot on. Fettled the IF, alignment too. My Siglent Arb only goes up to 120MHz, but I used my spectrum analyser and a near-field probe to measure the LO frequencies directly.

One thing I've noticed is that the picture looks a little soft in the horizontal. I'll be looking into that when I've recovered a bit from the surgery.

[Mike Watterson]

I think that's a characteristic of the low bandwidth of 405 lines. Depends how soft it is.