G8 buzz on sound. - UK Vintage Radio Repair and Restoration Discussion Forum

ekcopyephilips · 29th Feb 2008, 10:24 pm

Hi all
I wonder if anyone can explain the following to me. This afternoon whilst laying on my bed watching Richard and Judy on my Philips G8 (combined IF & chroma panel), I noticed the following.

All was fine until an advert for Norwich Union Direct came on and they put some small legal text on the bottom of the screen. Whenever this was displayed during the advert, there was a buzzing almost like a mistuned channel coming from the speaker: whenever the text was off the screen sound was normal. Why does this happen, is it a fault ? Do other makes of set of this era suffer the same problem?

Mike Burton

Tazman1966 · 29th Feb 2008, 11:15 pm

Hi Mike.

Maybe the G8 was protesting at having to display Richard & Judy

Seriously though, my G8 (G22K551) also had "caption buzz" although I managed to almost competely tune it out by tweaking the cores in the sound IF module. The paper sticky label that covers them up already had holes poked in it to allow this! In other words, someone had already had a go

!

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If you click on the thumbnail above you'll see which one I mean.

I've also noticed that it is not present at all if we're using the RF output of the Sky box.

Hope this helps.

Steve_P · 29th Feb 2008, 11:38 pm

Ah, the BRC1500 problem!

Caption Buzz is easier to eliminate in a G8, but why was it turned in the first place?

If you can't get rid of it, check on TP2 and change the caps around the transistor 506. This lot are all on the board inside the can I'm afraid. Has it been apart?

Cheers,

Steve P

Tim · 1st Mar 2008, 12:26 am

I used to get this on our Decca Bradford.

Steve_P · 1st Mar 2008, 12:31 am

We might get this sort of thing a bit more now. In the analogue transmissions, the modulator was a lot more precise, and VSB. Now we need a modulator in whatever box we are going to run the set off. And they are cheap, as most people use scart now anyway.

Just a thought to kick about.

Cheers,

Steve P

29th Feb 2008, 10:24 pm	#1
ekcopyephilips Hexode Join Date: Dec 2006 Location: Norwich, Norfolk, UK. Posts: 440	G8 buzz on sound. Hi all I wonder if anyone can explain the following to me. This afternoon whilst laying on my bed watching Richard and Judy on my Philips G8 (combined IF & chroma panel), I noticed the following. All was fine until an advert for Norwich Union Direct came on and they put some small legal text on the bottom of the screen. Whenever this was displayed during the advert, there was a buzzing almost like a mistuned channel coming from the speaker: whenever the text was off the screen sound was normal. Why does this happen, is it a fault ? Do other makes of set of this era suffer the same problem? Mike Burton Last edited by Mike Phelan; 4th Mar 2009 at 11:51 am. Reason: Typos corrected

29th Feb 2008, 11:15 pm	#2
Tazman1966 Nonode Join Date: May 2006 Location: St Albans, Herts, UK. Posts: 2,193	Re: G8 buzz on sound ? Hi Mike. Maybe the G8 was protesting at having to display Richard & Judy Seriously though, my G8 (G22K551) also had "caption buzz" although I managed to almost competely tune it out by tweaking the cores in the sound IF module. The paper sticky label that covers them up already had holes poked in it to allow this! In other words, someone had already had a go! If you click on the thumbnail above you'll see which one I mean. I've also noticed that it is not present at all if we're using the RF output of the Sky box. Hope this helps. __________________ All the very best, Tas

29th Feb 2008, 11:38 pm	#3
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: G8 buzz on sound ? Ah, the BRC1500 problem! Caption Buzz is easier to eliminate in a G8, but why was it turned in the first place? If you can't get rid of it, check on TP2 and change the caps around the transistor 506. This lot are all on the board inside the can I'm afraid. Has it been apart? 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...? Last edited by Steve_P; 29th Feb 2008 at 11:44 pm.

1st Mar 2008, 12:26 am	#4
Tim Dekatron Join Date: Jan 2003 Location: Bradford on Avon, Wiltshire, UK. Posts: 3,310	Re: G8 buzz on sound ? I used to get this on our Decca Bradford. __________________ "Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."

1st Mar 2008, 12:31 am	#5
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: G8 buzz on sound ? We might get this sort of thing a bit more now. In the analogue transmissions, the modulator was a lot more precise, and VSB. Now we need a modulator in whatever box we are going to run the set off. And they are cheap, as most people use scart now anyway. Just a thought to kick about. 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...?