What was your favorite regional ITV station growing up?

Not sure, remember relay and 'secondary' VHF main stations in a given region were off air or SHF fed from the primary one, and I think post 1968 the only 'dual region' ITV companies were HTV and Southern ? So in that case for HTV both of theirs would have gone to St Hilary (which transmitted both the Wales and West regions on VHF). Not sure about Dover, 'bluecortina' might know ?

On the basis that there were more main transmitters than studios, they would have required additional converters. Maybe there was a brand new converter at Chillerton Down and the one from the studios went to Dover with the option to RBS Chillterton if it wasn't ready in time?

Receiving Chillerton at Dover would have been difficult, Mendlesham (Anglia) was co channel on Ch 11, and it's a hell of a distance (even for VHF). (Edit: Back then the drive from Southampton to Dover was horrendous, it would take forever, even today you're better off going M3-M25-M20) !!
Dover was SHF fed, via London. Not sure how things worked in the 405 era, but in 625 era, Dover studio was a remote source into Southampton, and the Dover Tx fed from Southampton. Commercials for both halves of the region were played out from Southampton.

Ah, I hadn't realised the commercials were split, which would mean there were two converters required anyway.

You allude to the converters not being so reliable, is it possible that they had a main/standby pair setup and they were moved in stages?

Could have dealt with that a tad more gently, Noel.

That's very likely, the plan anyway would have been to have had them at the Tx sites. I suspect having them at the studios was only a short term temporary interim arrangement anyway ?

I assume that the history was that every station was operating on 405 lines, with the studio to transmitter links in 405.
Then the studio centres were converted to 625 line operation, and that was when the standards convertors were put in place in their MCRs to downconvert to the 405 line distribution, which in the cases of HTV and Southern would require two for split operation.
As their primary tx at that time were 405, then this was a critical part of the distribution, and every station must have had a main and spare, or you were off air due to a single fault.
Were the existing circuits upgraded to be able to operate at 625 as the Post Office was able to prior to S day, or were new ones put in place, and the original circuits ceased afterwards? When the main tx moved site, from Croydon to CP or Lichfield to SC, it had to be a new circuit I imagine?
Where in those cases did the standards converter go - 625 line to CP or SC, and downconverted there before being sent to the 405 line tx? Was there no one plan fits all stations?
A bit of history that is quite interesting!

The ITA/IBA architecture from 1969 onwards was that the ITA's primary transmitter in each region had a Colour Control Room, these were upgraded from the 405 line facilities, and included slide scanners and audio equipment to radiate test cards and music etc out of hours. The standards converters were moved to these locations too. Therefore the incoming lines from the regional ITV station came to these sites, and in the case where the UHF transmitter wasn't at the same site, then a further circuit ran from the ITA CCR to the UHF site (usually this was a BBC site) Examples; Croydon to CP, Lichfield to Sutton Coldfield, Chillerton to Rowridge). Obviously in other regions where the ITA site was selected for UHF it was all self contained (Emley, Winter Hill, Black Hill, Caradon Hill etc)

This arrangement allowed the ITA to radiate different test cards on VHF and UHF, and during test transmissions leading up to the magic Nov 1969 date; they'd replace the ad breaks on UHF/625 with Test Card F

You're right, it's a fascinating period.

Of course, the testcards would need to be different, so couldn't be derived from the same feed. I had missed that!
There must be information about the circuits somewhere, either in the ITA / IBA or Post Office archives.
I was always told that some of the BBC's rented circuits between Birmingham and Norwich were the original 405 line ones that had been upgraded, but were not the best. They were later replaced with feeds between London and Norwich.

Certainly when a JCB building the A38 cut through the cable carrying BBC Plymouth's BT circuits in 1986 they were able to reequalise the disused 405 line cable that took a different route to the later cables.

http://wiki.tx.mb21.co.uk/index.php?title=Down_the_Tubes#Temporary_solution

Yorkshire Television had two shops, in Lincoln and York, both now closed, which sold various gifts, memorabilia, and other things like Yorkshire Television umbrellas! Did any other ITV company have shops selling such stuff?

In around 2004 Yorkshire television moved their offices from Bailgate (where the shop also was) to the University of Lincoln campus, where ironically, the internal television distribution carried Central.