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Old 26th Jul 2019, 12:09 am   #200
Join Date: Aug 2009
Location: High Wycombe, Bucks. UK.
Posts: 488
Default Re: Hedghog standards converter

Originally Posted by 1100 man View Post
By the time your TV's were sold in the UK (late '70's or early '80's), 405 would have been considered a 'legacy' system. I'm always amazed there was such a long transition time and that 405 dragged on for so long. As long as the new tv's could receive the new UHF transmissions, it didn't matter that they also came with incompatible VHF tuners. Manufacturers weren't going to remove them just for the UK!
Quite a lot of the imported B/W portable TVs were sold in the UK without the VHF tuner which would normally have been fitted for other countries. Usually the hole for the VHF tuner on the front of the set was covered up by a badge saying "Portable Deluxe" "I.C. Mains/Battery" or similar boast. I have an unusual ""Cihan" 17 inch B/W portable TV imported from Turkey which still has the VHF tuner inside, but the knob has been removed and the hole covered up. They couldn't remove the VHF tuner completely, since the I.F. strip appears to be part of it. Removing the VHF tuner on UK models was desirable from the manufacturer's point of view. Not only it saved the cost of the tuner, it also avoided customers accidentally switching to VHF and then complaining that the TV is faulty, it can't get a picture.

Sets with 625 VHF were useful for visiting Ireland on holiday, or other European countries if a 5.5 / 6.0 MHz sound system switch was provided. This was often a selling point for small portable TVs that you could take on holiday with you. 625 VHF TVs were sought after by DX-TV enthusiasts in the UK, hoping to catch a glimpse of foreign TV signals given the right atmospheric conditions. Many cable TV networks in the UK used 625 VHF as well. Normally the cable operator supplied a VHF to UHF converter box, but if your TV or VCR could tune VHF, you could avoid the need to buy or rent an extra converter box.

If you want to run your 625 line TV on VHF, it's easy. You just need a suitable modulator and 625 line source such as a DVD player, digital set top box etc. The Hedghog modulator is not suitable, it's designed for System A. You need one that is System I (or B/G if your TV has a 5.5 / 6MHz sound system switch). A possible example is here:

(I don't own that product and can't personally vouch for it, but I'm sure someone else can recommend you a suitable VHF modulator for your 625 line sets.) I have another device called A2B Multibox which is a 3-channel Freeview receiver and VHF/UHF modulator in one. It works, but was a bit fiddly to set up.

You could of course get a real 405-line or dual standard 405/625 TV to go with your Hedghog. The Sony 9-90UB has already been mentioned. There are quite many of them around, they cost no more than 10-20 and surprisingly usually still work, despite being 50 years old.
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