Aurora to Pye B18T - UK Vintage Radio Repair and Restoration Discussion Forum

YoungManGW · 3rd Jun 2012, 12:24 pm

Dear All,
I would be grateful for a little help re. the final stage of connecting my working Pye B18T television, via an Aurora, to a Freeview digibox. The digibox is connected to the Aurora, and this has the required power supply. 75 ohm co-axial cable is connected to the Aurora with a F-type RF connector. But how do I connect the other end of the co-axial cable to the TV, which has a twin line aerial connection? Can anyone recommend please a suitable connection, and/or point me in the direction of one?
Thank-you,
Richard

Framer Dave · 3rd Jun 2012, 12:59 pm

You need a Balun, a device intended to convert from 300Ω balanced twin feeder to 75Ω co-axial cable, which, connected in reverse, will do what you want. This device can be otained from, for example, Maplin for about £2.50, part no. FD78K. You will also ideally need a short piece of 300Ω feeder but two short pieces of wire should be fine.

Fit a Belling-Lee type coax plug to the cable from your Aurora together with a female-female coax adaptor. Plug one into the other and connect the two terminals on the balun to your B18T's aerial connections. That should do it.

Pease be aware that the output from the Aurora is at a high level, and it may be necessary to insert an attenuator between it and the balun to avoid overloading the set's front end.

HTH

YoungManGW · 3rd Jun 2012, 1:24 pm

Thank-you for that Dave, much appreciated. Would it be wise to insert the attenuator, fitted before the balun, into the coaxial feed from the Aurora before connecting everything up? In other words, is this something I should do to be on the safe side to protect the B18T, or a nice-to-have addition to get the best result? I am just down the road from you, in Oswestry, BTW.
Regards,
Richard

Framer Dave · 3rd Jun 2012, 1:48 pm

Hi Richard,

You will do no harm to your set if the signal level is too high, indeed there will be a loss incurred in using the balun. I would suggest "suck it and see" first. You can always get an attenuator later.

Regards,

YoungManGW · 3rd Jun 2012, 2:13 pm

Thank-you - you advice is much appreciated. Will give it all a whirl.

Boom · 3rd Jun 2012, 2:21 pm

I've never used a balun with the B18 and it works.

YoungManGW · 3rd Jun 2012, 4:37 pm

Boom Dave - how have you connected the coaxial cable from the Aurora to the twin line aerial connections of the B18T? Being a bit of a neat-freak, I am looking to do this in as elegant a way as is possible. Many thanks.

Boom · 3rd Jun 2012, 7:03 pm

I just put the inner in one hole and the screen in the other hole. Doesn't matter which way around.

petertheorgan · 3rd Jun 2012, 9:37 pm

I agree , you will have loads of signal , I just soldered on a few inches of wire to the end of the coax and fitted a couple of wander plugs

PS dont forget to check that the chassis is not live !

Andy Doz · 11th Jun 2012, 12:30 pm

The aerial socket is transformer isolated in the B18 / BV20/ LV 20 etc , so no worries there...

3rd Jun 2012, 12:24 pm	#1
YoungManGW Hexode Join Date: Dec 2011 Location: Oswestry, Shropshire, UK. Posts: 408	Aurora to Pye B18T Dear All, I would be grateful for a little help re. the final stage of connecting my working Pye B18T television, via an Aurora, to a Freeview digibox. The digibox is connected to the Aurora, and this has the required power supply. 75 ohm co-axial cable is connected to the Aurora with a F-type RF connector. But how do I connect the other end of the co-axial cable to the TV, which has a twin line aerial connection? Can anyone recommend please a suitable connection, and/or point me in the direction of one? Thank-you, Richard

3rd Jun 2012, 12:59 pm	#2
Framer Dave Rest in Peace Join Date: Dec 2006 Location: Near Wrecsam, North Wales Posts: 356	Re: Aurora to Pye B18T You need a Balun, a device intended to convert from 300Ω balanced twin feeder to 75Ω co-axial cable, which, connected in reverse, will do what you want. This device can be otained from, for example, Maplin for about £2.50, part no. FD78K. You will also ideally need a short piece of 300Ω feeder but two short pieces of wire should be fine. Fit a Belling-Lee type coax plug to the cable from your Aurora together with a female-female coax adaptor. Plug one into the other and connect the two terminals on the balun to your B18T's aerial connections. That should do it. Pease be aware that the output from the Aurora is at a high level, and it may be necessary to insert an attenuator between it and the balun to avoid overloading the set's front end. HTH

3rd Jun 2012, 1:24 pm	#3
YoungManGW Hexode Join Date: Dec 2011 Location: Oswestry, Shropshire, UK. Posts: 408	Re: Aurora to Pye B18T Thank-you for that Dave, much appreciated. Would it be wise to insert the attenuator, fitted before the balun, into the coaxial feed from the Aurora before connecting everything up? In other words, is this something I should do to be on the safe side to protect the B18T, or a nice-to-have addition to get the best result? I am just down the road from you, in Oswestry, BTW. Regards, Richard

3rd Jun 2012, 1:48 pm	#4
Framer Dave Rest in Peace Join Date: Dec 2006 Location: Near Wrecsam, North Wales Posts: 356	Re: Aurora to Pye B18T Hi Richard, You will do no harm to your set if the signal level is too high, indeed there will be a loss incurred in using the balun. I would suggest "suck it and see" first. You can always get an attenuator later. Regards,

3rd Jun 2012, 2:13 pm	#5
YoungManGW Hexode Join Date: Dec 2011 Location: Oswestry, Shropshire, UK. Posts: 408	Re: Aurora to Pye B18T Thank-you - you advice is much appreciated. Will give it all a whirl.

3rd Jun 2012, 2:21 pm	#6
Boom Retired Dormant Member Join Date: Jan 2007 Location: Westbury, Wiltshire, UK. Posts: 2,451	Re: Aurora to Pye B18T I've never used a balun with the B18 and it works.

3rd Jun 2012, 4:37 pm	#7
YoungManGW Hexode Join Date: Dec 2011 Location: Oswestry, Shropshire, UK. Posts: 408	Re: Aurora to Pye B18T Boom Dave - how have you connected the coaxial cable from the Aurora to the twin line aerial connections of the B18T? Being a bit of a neat-freak, I am looking to do this in as elegant a way as is possible. Many thanks.

3rd Jun 2012, 7:03 pm	#8
Boom Retired Dormant Member Join Date: Jan 2007 Location: Westbury, Wiltshire, UK. Posts: 2,451	Re: Aurora to Pye B18T I just put the inner in one hole and the screen in the other hole. Doesn't matter which way around.

3rd Jun 2012, 9:37 pm	#9
petertheorgan Hexode Join Date: Dec 2006 Location: Bromley, Kent, UK. Posts: 332	Re: Aurora to Pye B18T I agree , you will have loads of signal , I just soldered on a few inches of wire to the end of the coax and fitted a couple of wander plugs PS dont forget to check that the chassis is not live !

11th Jun 2012, 12:30 pm	#10
Andy Doz Hexode Join Date: Feb 2011 Location: Gloucestershire, UK. Posts: 376	Re: Aurora to Pye B18T The aerial socket is transformer isolated in the B18 / BV20/ LV 20 etc , so no worries there...