Pam 606s - UK Vintage Radio Repair and Restoration Discussion Forum

Tazman1966 · 17th Jul 2013, 10:46 am

Good morning telly fans!

I mentioned in post 16 of this thread that I'd been given a Pam set to play with. It had been in my Mother-in-law's friends family from new in they think 1961 and was used throughout the 1960s and into 1970. It became a "second set" until the late 70s when it was put away in the loft "just in case"!

As explained, I threw caution to the wind and plugged it in and it sort of worked. I had thought that there may have been some interesting tales to tell about the restoration but it was just routine servicing work.

I first dismantled the set and gave the cabinet and Polaroid implosion screen a good clean. All the dust and cobwebs got vacuumed out with the aid of a soft long bristled paintbrush.

As far as component replacement went, the first port of call was the line timebase begining with the tricky to get to boost cap and scan coil coupling capacitor mounted at the back of the LOPT. The CRT needed to be removed to facilitate this. It was worth it though in order to give the innards a right good clean. With these replaced along with the line osc coupling cap, we now had full width which stayed full! The boost cap was amazingly leaky. It's a wonder the line stage worked at all. The sync was still poor though so replacement of the sync coupling capacitor sorted that out.

Next the frame timebase non-linearity responded to blanket cap replacement including the frame output valve's cathode by-pass electrolytic (open circuit) and cathode resistor (overheated and reduced in value from 330ohms to 200). A couple of scorched resistors feeding the frame stages were replaced too. I gave the pots a good run through with cleaner as well.

Over on the video/IF board a couple of dodgy valve holders were given a clean which improved intermittent sound signals and the remaining waxies were all replaced. This included the video to CRT coupler which promptly went short circuit while I was running the set up after the frame stage work. It caused an over bright picture which could not be adjusted.

I took the cover off the tuner and cleaned up all the contacts - it was VERY intermittent.

The set needed no new valves at all although there was evidence of replacements in the past with brands such as Mazda, Pinnacle and Brimar in place. I also decided not to replace the metal HT rectifier as the HT is very stable and well up to scratch.

The set was then re-assembled, given a good old polish and that was that. This account makes it seem like I did it all in one go but it took a while as the workshop is like an oven at the moment!

Here are some pics of the innards...

Tazman1966 · 17th Jul 2013, 10:49 am

And the rest of the pictures...

Steve_P · 17th Jul 2013, 12:21 pm

Interesting set, as it looks identical to Pye sets of the same era, one of which I repaired lately. Nicer looking set, though.

Cheers,

Steve P.

mark pirate · 17th Jul 2013, 12:30 pm

The chassis looks very close to the Pam 600F I restored earlier this year, I found recapping the PCB's nice and simple, but the caps mounted on the LOPT were a bit of a pain!

They do produce an excellent picture, my tuner also needed attention, one of the wafers was covered in some green corrosion, but cleaned up fine.

Nice to see another Polaroid screen set working well

Mark

Focus Diode · 17th Jul 2013, 1:58 pm

Another excellent restoration job Tas, well done.

Cheers,
Brian

akuram1 · 17th Jul 2013, 3:36 pm

Pam sets always looked better finished than Pye for some reason which I never understood.

Heatercathodeshort · 17th Jul 2013, 5:22 pm

That looks great Tas. Is it a Polaroid screen? The Pam 600 series with P screens tended to look completely black when turned off, a bit like the KB Deep Scene. Nice linearity, better now than when quite new as the wax caps leaked when only a few years old. I always had a soft spot for Pam. Regards, John.

Peter.N. · 17th Jul 2013, 7:13 pm

Is it just me or is a 90 degree set with a metal rectifier unusual?

Peter

Tazman1966 · 17th Jul 2013, 11:34 pm

Thanks for all the comments guys

Sure enough Mark, the caps on the back of the LOPT were an absolute pig to do but managed to after removing the CRT. It was even quite a neat job eventually (if I do say so myself

)

Sure is a Polaroid screen John. There's a sticker on the inside of the back cover explaining about making sure it's the right way round. It is sark when off but nowhere near as black as the KB Deep Scene etc.

Hi Peter. It's not a 90° tube, it's 110° Mullard AW43-88 and apart from a little defocussing at the edges, it's in good nick

Peter.N. · 18th Jul 2013, 10:01 am

Quote:

Originally Posted by Tazman1966

Thanks for all the comments guys

Sure enough Mark, the caps on the back of the LOPT were an absolute pig to do but managed to after removing the CRT. It was even quite a neat job eventually (if I do say so myself

)

Sure is a Polaroid screen John. There's a sticker on the inside of the back cover explaining about making sure it's the right way round. It is sark when off but nowhere near as black as the KB Deep Scene etc.

Hi Peter. It's not a 90° tube, it's 110° Mullard AW43-88 and apart from a little defocussing at the edges, it's in good nick

Even more unusual, I only remember metal recs in 90 degree sets.

Peter

Heatercathodeshort · 18th Jul 2013, 7:21 pm

They were quite common as Peter suggests. GEC and Murphy come to mind in huge quantities. 110 degree models also had 'finned' rectifiers. J.

17th Jul 2013, 10:46 am	#1
Tazman1966 Nonode Join Date: May 2006 Location: St Albans, Herts, UK. Posts: 2,193	Pam 606s Good morning telly fans! I mentioned in post 16 of this thread that I'd been given a Pam set to play with. It had been in my Mother-in-law's friends family from new in they think 1961 and was used throughout the 1960s and into 1970. It became a "second set" until the late 70s when it was put away in the loft "just in case"! As explained, I threw caution to the wind and plugged it in and it sort of worked. I had thought that there may have been some interesting tales to tell about the restoration but it was just routine servicing work. I first dismantled the set and gave the cabinet and Polaroid implosion screen a good clean. All the dust and cobwebs got vacuumed out with the aid of a soft long bristled paintbrush. As far as component replacement went, the first port of call was the line timebase begining with the tricky to get to boost cap and scan coil coupling capacitor mounted at the back of the LOPT. The CRT needed to be removed to facilitate this. It was worth it though in order to give the innards a right good clean. With these replaced along with the line osc coupling cap, we now had full width which stayed full! The boost cap was amazingly leaky. It's a wonder the line stage worked at all. The sync was still poor though so replacement of the sync coupling capacitor sorted that out. Next the frame timebase non-linearity responded to blanket cap replacement including the frame output valve's cathode by-pass electrolytic (open circuit) and cathode resistor (overheated and reduced in value from 330ohms to 200). A couple of scorched resistors feeding the frame stages were replaced too. I gave the pots a good run through with cleaner as well. Over on the video/IF board a couple of dodgy valve holders were given a clean which improved intermittent sound signals and the remaining waxies were all replaced. This included the video to CRT coupler which promptly went short circuit while I was running the set up after the frame stage work. It caused an over bright picture which could not be adjusted. I took the cover off the tuner and cleaned up all the contacts - it was VERY intermittent. The set needed no new valves at all although there was evidence of replacements in the past with brands such as Mazda, Pinnacle and Brimar in place. I also decided not to replace the metal HT rectifier as the HT is very stable and well up to scratch. The set was then re-assembled, given a good old polish and that was that. This account makes it seem like I did it all in one go but it took a while as the workshop is like an oven at the moment! Here are some pics of the innards... Attached Thumbnails __________________ All the very best, Tas

17th Jul 2013, 10:49 am	#2
Tazman1966 Nonode Join Date: May 2006 Location: St Albans, Herts, UK. Posts: 2,193	Re: Pam 606s And the rest of the pictures... Attached Thumbnails __________________ All the very best, Tas

17th Jul 2013, 12:21 pm	#3
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Pam 606s Interesting set, as it looks identical to Pye sets of the same era, one of which I repaired lately. Nicer looking set, though. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

17th Jul 2013, 12:30 pm	#4
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Pam 606s The chassis looks very close to the Pam 600F I restored earlier this year, I found recapping the PCB's nice and simple, but the caps mounted on the LOPT were a bit of a pain! They do produce an excellent picture, my tuner also needed attention, one of the wafers was covered in some green corrosion, but cleaned up fine. Nice to see another Polaroid screen set working well Mark

17th Jul 2013, 1:58 pm	#5
Focus Diode Octode Join Date: Jan 2006 Location: Borough of Gateshead, UK. Posts: 1,420	Re: Pam 606s Another excellent restoration job Tas, well done. Cheers, Brian

17th Jul 2013, 3:36 pm	#6
akuram1 Pentode Join Date: Sep 2009 Location: Dundee, UK. Posts: 158	Re: Pam 606s Pam sets always looked better finished than Pye for some reason which I never understood.

17th Jul 2013, 5:22 pm	#7
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Pam 606s That looks great Tas. Is it a Polaroid screen? The Pam 600 series with P screens tended to look completely black when turned off, a bit like the KB Deep Scene. Nice linearity, better now than when quite new as the wax caps leaked when only a few years old. I always had a soft spot for Pam. Regards, John.

17th Jul 2013, 7:13 pm	#8
Peter.N. Dekatron Join Date: Jul 2008 Location: Charmouth, Dorset, UK. Posts: 3,601	Re: Pam 606s Is it just me or is a 90 degree set with a metal rectifier unusual? Peter

17th Jul 2013, 11:34 pm	#9
Tazman1966 Nonode Join Date: May 2006 Location: St Albans, Herts, UK. Posts: 2,193	Re: Pam 606s Thanks for all the comments guys Sure enough Mark, the caps on the back of the LOPT were an absolute pig to do but managed to after removing the CRT. It was even quite a neat job eventually (if I do say so myself ) Sure is a Polaroid screen John. There's a sticker on the inside of the back cover explaining about making sure it's the right way round. It is sark when off but nowhere near as black as the KB Deep Scene etc. Hi Peter. It's not a 90° tube, it's 110° Mullard AW43-88 and apart from a little defocussing at the edges, it's in good nick __________________ All the very best, Tas

18th Jul 2013, 7:21 pm	#11
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Pam 606s They were quite common as Peter suggests. GEC and Murphy come to mind in huge quantities. 110 degree models also had 'finned' rectifiers. J.