Advice please...boombox aerial related. - UK Vintage Radio Repair and Restoration Discussion Forum

elliott · 31st Dec 2018, 5:58 pm

Hi to everyone,

I'm new here and like all noobs i'm starting with a question(sorry)...

Basically I just bought an old 80's boombox with built in TV. It's a Goodmans Quadro 907. My plan was to repair the various faults and then connect it to either an old VHS player or use a modulator of some type. It's going to be living in my workshop and I liked the idea of watching old black and white movies whilst working away! Anyways, after getting stuck in and fixing a few of the faults I thought it time to test the TV function by connecting it to the RF outlet of my Sky box. This is where my problem came. I don't know why I had checked it but there is no coaxial plug on the unit at all. There is the standard telescopic aerial and a separate 'Ext Ant' port...which looks like a 3.5mm jack port. I've never seen anything like it, though I must admit I haven't spent much time working with old TV's. So my question(s) is(are)...what type of connection is this?...Google offered no help here. Is there an adapter available to take it to a standard RF connection or am I going to need to open it up and hot wire one in?

Really hope someone can help out, thanks a lot

Elliott

paulsherwin · 31st Dec 2018, 6:13 pm

It probably is just a 3.5mm jack socket. You need to solder a plug on one end of a length of coax, and put a standard Belling coax plug on the other end. The signal will go to the tip.

60 oldjohn · 31st Dec 2018, 6:27 pm

As Paul says or if you have to send off for the parts this is available.

John.

https://www.ebay.co.uk/sch/i.html?_o...ocket&_sacat=0

elliott · 31st Dec 2018, 6:31 pm

Wow, super fast replies, I really appreciate it, thanks. Time to get the soldering iron warmed up! thanks again.

elliott · 31st Dec 2018, 8:48 pm

OK.

I made up a cable by cutting one end off of a working coaxial cable and soldering on a 2 conductor 3.5mm jack. Tried it out and I can tune it so that I have perfect sound but the picture just won't come on. It's trying; almost as if it's a really weak signal, but I know the RF outlet I'm testing it with is high strength. My knowledge of these things is limited but my soldering skills are good and I made sure the connections were good, shrink tubed it to reinforce it and checked the continuity so that's all good.

Any ideas?

Clydeuk · 31st Dec 2018, 10:04 pm

What are you using as a source? There should be enough gain for this to produce a picture when the centre conductor is held against the telescopic aerial, possibly even just held close. I would try that first. It's possible there is a fault with the socket or tuner, but before you condemn it it would be worth trying a ready made connector as in the link in post 3 above.

Clydeuk · 31st Dec 2018, 10:06 pm

Forgot to mention, if the device you're using as a source has a tunable output, try a few different output channels as it is possible the output is clashing with a digital MUX off the air being picked up by the telescopic aerial.

paulsherwin · 31st Dec 2018, 10:14 pm

Also, check if the TV supports multiple TV standards, and if it does that it is set for the UK system (PAL-I).

Graham G3ZVT · 31st Dec 2018, 11:48 pm

Quote:

Originally Posted by elliott

I made up a cable by cutting one end off of a working coaxial cable and soldering on a 2 conductor 3.5mm jack. Tried it out and I can tune it so that I have perfect sound but the picture just won't come on. It's trying; almost as if it's a really weak signal, but I know the RF outlet I'm testing it with is high strength.

Can you take a picture of what's on the screen and post it here?

AndiiT · 31st Dec 2018, 11:59 pm

Quote:

Originally Posted by elliott

....'Ext Ant' port...which looks like a 3.5mm jack port. ......

Hi, From memory these units may have been supplied with an adaptor similar to the one shown in the following link https://www.ebay.co.uk/itm/3-5mm-MON...YMxx:rk:3:pf:0

Regards

Andrew

phut bang · 1st Jan 2019, 11:09 am

the small b&w tv i use in my shed has the same 3.5 aerial socket and i have a 3.5 to female coax plug adaptor i use on it cant remeber where i had it from though but it should be easy to make alead up

elliott · 2nd Jan 2019, 10:38 pm

Thanks to all again for the advice. I have ordered the 3.5mm jack adapter as well as a modulator so I can run off of a DVD player without the VHS hassle.

The source i'm using is the IO RF outlet on a Sky+ box. I'm using an IO link direct from the outlet which then feeds the Boombox TV. I made up a new length of coaxial cable and left the Boombox feed end with just the core protruding. Unfortunately when i touch this to the telescopic antenna I stil can't get it to tune in. I've attached some photos below to show what i'm getting on the screen. The sound is perfect, but it would be nice to have a picture to go with it

I've tried multiple channels out to try and eliminate the possibility of interference but no change.

I believe the unit was a UK only product and theres no NTSC/PAL switch or anything so that shouldn't be an issue.

I'm at a loss. Worse case scenario I'll track down another one as I really want one in my workshop and the modulator will still be essential, but it would be nice to get this one working. Any more ideas would be gratefully appreciated.

Spent a bit of time looking through the forums here and really glad I stumbled upon it!

Clydeuk · 3rd Jan 2019, 1:41 am

Is there a horizontal hold (or line hold) control visible anywhere? Maybe at the back of the unit? The third picture looks like it might need a tweak. It appears to be tuned in.

Graham G3ZVT · 3rd Jan 2019, 2:25 am

I'm feeling slightly smug, because I wondered when I asked for some screenshots if they would show a line or frame hold malagustment.

For those of us who grew up with black and White and early colour CRT sets we knew how to adjust the horizontal and vertical hold as necessary. I mean humble viewers, not technicians.

But it's been decades since sets have been manufactured that need such controls. So it's not surprising the problem isn't identified for what it is, on an old CRT set.

It's often the case that the present pots for horizontal and vertical hold can be reached through holes in the back cover.

elliott · 3rd Jan 2019, 7:19 am

This was my first thought as my first TV as a kid had these adjustment knobs and I remember well having to fine tune them. Unfortunately on this TV it seems to make no difference. I know the pots are working as when I turn them it does change (what I assume is) the frequency, as well as the vertical margins, but still fails to show any kind of picture.

Graham G3ZVT · 5th Jan 2019, 3:28 pm

Is the chassis anything like this "902"?

https://www.experimental-engineering...ite-video-mod/

If so, the preset you are after is not one on the rear edge of the board, and may be marked SVR2.

31st Dec 2018, 5:58 pm	#1
elliott Retired Dormant Member Join Date: Dec 2018 Location: Chichester, West Sussex, UK. Posts: 5	Advice please...boombox aerial related. Hi to everyone, I'm new here and like all noobs i'm starting with a question(sorry)... Basically I just bought an old 80's boombox with built in TV. It's a Goodmans Quadro 907. My plan was to repair the various faults and then connect it to either an old VHS player or use a modulator of some type. It's going to be living in my workshop and I liked the idea of watching old black and white movies whilst working away! Anyways, after getting stuck in and fixing a few of the faults I thought it time to test the TV function by connecting it to the RF outlet of my Sky box. This is where my problem came. I don't know why I had checked it but there is no coaxial plug on the unit at all. There is the standard telescopic aerial and a separate 'Ext Ant' port...which looks like a 3.5mm jack port. I've never seen anything like it, though I must admit I haven't spent much time working with old TV's. So my question(s) is(are)...what type of connection is this?...Google offered no help here. Is there an adapter available to take it to a standard RF connection or am I going to need to open it up and hot wire one in? Really hope someone can help out, thanks a lot Elliott

31st Dec 2018, 6:13 pm	#2
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,967	Re: Advice please...boombox aerial related. It probably is just a 3.5mm jack socket. You need to solder a plug on one end of a length of coax, and put a standard Belling coax plug on the other end. The signal will go to the tip.

31st Dec 2018, 6:27 pm	#3
60 oldjohn Dekatron Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 3,988	Re: Advice please...boombox aerial related. As Paul says or if you have to send off for the parts this is available. John. https://www.ebay.co.uk/sch/i.html?_o...ocket&_sacat=0

31st Dec 2018, 6:31 pm	#4
elliott Retired Dormant Member Join Date: Dec 2018 Location: Chichester, West Sussex, UK. Posts: 5	Re: Advice please...boombox aerial related. Wow, super fast replies, I really appreciate it, thanks. Time to get the soldering iron warmed up! thanks again.

31st Dec 2018, 8:48 pm	#5
elliott Retired Dormant Member Join Date: Dec 2018 Location: Chichester, West Sussex, UK. Posts: 5	Re: Advice please...boombox aerial related. OK. I made up a cable by cutting one end off of a working coaxial cable and soldering on a 2 conductor 3.5mm jack. Tried it out and I can tune it so that I have perfect sound but the picture just won't come on. It's trying; almost as if it's a really weak signal, but I know the RF outlet I'm testing it with is high strength. My knowledge of these things is limited but my soldering skills are good and I made sure the connections were good, shrink tubed it to reinforce it and checked the continuity so that's all good. Any ideas?

31st Dec 2018, 10:04 pm	#6
Clydeuk Hexode Join Date: Mar 2012 Location: Liverpool, Merseyside, UK. Posts: 453	Re: Advice please...boombox aerial related. What are you using as a source? There should be enough gain for this to produce a picture when the centre conductor is held against the telescopic aerial, possibly even just held close. I would try that first. It's possible there is a fault with the socket or tuner, but before you condemn it it would be worth trying a ready made connector as in the link in post 3 above.

31st Dec 2018, 10:06 pm	#7
Clydeuk Hexode Join Date: Mar 2012 Location: Liverpool, Merseyside, UK. Posts: 453	Re: Advice please...boombox aerial related. Forgot to mention, if the device you're using as a source has a tunable output, try a few different output channels as it is possible the output is clashing with a digital MUX off the air being picked up by the telescopic aerial.

31st Dec 2018, 10:14 pm	#8
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,967	Re: Advice please...boombox aerial related. Also, check if the TV supports multiple TV standards, and if it does that it is set for the UK system (PAL-I).

1st Jan 2019, 11:09 am	#11
phut bang Triode Join Date: Jan 2018 Location: Wrexham, Clwyd, Wales, UK. Posts: 47	Re: Advice please...boombox aerial related. the small b&w tv i use in my shed has the same 3.5 aerial socket and i have a 3.5 to female coax plug adaptor i use on it cant remeber where i had it from though but it should be easy to make alead up __________________ Adjust the volume for maximum smoke!

2nd Jan 2019, 10:38 pm	#12
elliott Retired Dormant Member Join Date: Dec 2018 Location: Chichester, West Sussex, UK. Posts: 5	Re: Advice please...boombox aerial related. Thanks to all again for the advice. I have ordered the 3.5mm jack adapter as well as a modulator so I can run off of a DVD player without the VHS hassle. The source i'm using is the IO RF outlet on a Sky+ box. I'm using an IO link direct from the outlet which then feeds the Boombox TV. I made up a new length of coaxial cable and left the Boombox feed end with just the core protruding. Unfortunately when i touch this to the telescopic antenna I stil can't get it to tune in. I've attached some photos below to show what i'm getting on the screen. The sound is perfect, but it would be nice to have a picture to go with it I've tried multiple channels out to try and eliminate the possibility of interference but no change. I believe the unit was a UK only product and theres no NTSC/PAL switch or anything so that shouldn't be an issue. I'm at a loss. Worse case scenario I'll track down another one as I really want one in my workshop and the modulator will still be essential, but it would be nice to get this one working. Any more ideas would be gratefully appreciated. Spent a bit of time looking through the forums here and really glad I stumbled upon it! Attached Thumbnails

3rd Jan 2019, 1:41 am	#13
Clydeuk Hexode Join Date: Mar 2012 Location: Liverpool, Merseyside, UK. Posts: 453	Re: Advice please...boombox aerial related. Is there a horizontal hold (or line hold) control visible anywhere? Maybe at the back of the unit? The third picture looks like it might need a tweak. It appears to be tuned in.

3rd Jan 2019, 2:25 am	#14
Graham G3ZVT Dekatron Join Date: May 2010 Location: Greater Manchester, UK. Posts: 18,724	Re: Advice please...boombox aerial related. I'm feeling slightly smug, because I wondered when I asked for some screenshots if they would show a line or frame hold malagustment. For those of us who grew up with black and White and early colour CRT sets we knew how to adjust the horizontal and vertical hold as necessary. I mean humble viewers, not technicians. But it's been decades since sets have been manufactured that need such controls. So it's not surprising the problem isn't identified for what it is, on an old CRT set. It's often the case that the present pots for horizontal and vertical hold can be reached through holes in the back cover. __________________ -- Graham. G3ZVT Last edited by Graham G3ZVT; 3rd Jan 2019 at 2:35 am.

3rd Jan 2019, 7:19 am	#15
elliott Retired Dormant Member Join Date: Dec 2018 Location: Chichester, West Sussex, UK. Posts: 5	Re: Advice please...boombox aerial related. This was my first thought as my first TV as a kid had these adjustment knobs and I remember well having to fine tune them. Unfortunately on this TV it seems to make no difference. I know the pots are working as when I turn them it does change (what I assume is) the frequency, as well as the vertical margins, but still fails to show any kind of picture.

5th Jan 2019, 3:28 pm	#16
Graham G3ZVT Dekatron Join Date: May 2010 Location: Greater Manchester, UK. Posts: 18,724	Re: Advice please...boombox aerial related. Is the chassis anything like this "902"? https://www.experimental-engineering...ite-video-mod/ If so, the preset you are after is not one on the rear edge of the board, and may be marked SVR2. __________________ -- Graham. G3ZVT Last edited by Graham G3ZVT; 5th Jan 2019 at 3:36 pm.