Set-top Aerial - UK Vintage Radio Repair and Restoration Discussion Forum

Murphy Maniac · 23rd Jul 2016, 7:26 pm

I have just obtained a new toy for my toy cupboard which may be of general interest. It is a small set-top aerial box containing a tunable ferrite rod aerial, switchable for use on either Long or Medium Wave. It is powered by a small 9V battery. Two wander plugs, one for the Aerial socket and one for the Earth socket on the back of the set in use and that is all that is needed to replace a long outside wire aerial and suck in lots of stations. Brilliant on the workbench. If anyone else is interested, I believe they will be available at the next Golborne.

paulsherwin · 23rd Jul 2016, 8:29 pm

I should have filed a patent: https://www.vintage-radio.net/forum/...read.php?t=579

Murphy Maniac · 24th Jul 2016, 12:26 am

You should indeed have done so, it is a brilliant idea and works so well...

Andrew2 · 24th Jul 2016, 10:31 am

Back in 1995 I had a 'MW booster' design published in SWM. It was very simple - a tuned ferrite rod aerial fed (directly from hot end of tuned cct) to G1 of a dual gate fet. G2 had a bias pot to adjust the gain.
Drain load was 2.2k and the source R was 560r.
Output was taken from the drain via a 0.1 cap and in this case fed a coupling coil which could be attached to the end of a portable radio, coupling by transformer action.
To help things along, a small feedback winding on the rod was fed via a 0.1uf from the source.
In use, once the required station was tuned and peaked, the gain pot would be advanced to just short of oscillation. The effect was dramatic and the tuning became very sharp. At the time I originally built it, there were a couple of naughty music stations that were pretty poor copy here in Cheshire, but with this thing adjusted for maximum smoke they came in like the proverbial ton of bricks.
September 1995, don't know if it's online anywhere.

mike g3zii · 25th Jul 2016, 8:35 pm

This is it. I developed this from a unit I made to receive the 80 meter ham band
without all the hash from switch mode rubbish and digi-junk, then I thought I'd try it on the broadcast bands. it has worked out very well. it runs on 6 AA batts
at less than 3mA including the LED. it's a ferrite rod aerial tuned across
160-1700 Khz amplified by a bf964 dual gate fet. the signal is choke capacitor coupled out to the radio on a screened lead.it's good with my tired old wartime civvy set which usually needs a 50 foot outside wire to get it to do much.
it lives in a 5 x 4 inch plastic box.
I am just getting the paperwork finished then I may start producing them in kit form,also ready built.

23rd Jul 2016, 7:26 pm	#1
Murphy Maniac Hexode Join Date: Aug 2009 Location: Liverpool, Merseyside, UK. Posts: 254	Set-top Aerial I have just obtained a new toy for my toy cupboard which may be of general interest. It is a small set-top aerial box containing a tunable ferrite rod aerial, switchable for use on either Long or Medium Wave. It is powered by a small 9V battery. Two wander plugs, one for the Aerial socket and one for the Earth socket on the back of the set in use and that is all that is needed to replace a long outside wire aerial and suck in lots of stations. Brilliant on the workbench. If anyone else is interested, I believe they will be available at the next Golborne. __________________ Geoff. (BVWS Member)

23rd Jul 2016, 8:29 pm	#2
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,943	Re: Set-top Aerial I should have filed a patent: https://www.vintage-radio.net/forum/...read.php?t=579

24th Jul 2016, 12:26 am	#3
Murphy Maniac Hexode Join Date: Aug 2009 Location: Liverpool, Merseyside, UK. Posts: 254	Re: Set-top Aerial You should indeed have done so, it is a brilliant idea and works so well... __________________ Geoff. (BVWS Member)

24th Jul 2016, 10:31 am	#4
Andrew2 Nonode Join Date: Mar 2010 Location: Dukinfield, Cheshire, UK. Posts: 2,037	Re: Set-top Aerial Back in 1995 I had a 'MW booster' design published in SWM. It was very simple - a tuned ferrite rod aerial fed (directly from hot end of tuned cct) to G1 of a dual gate fet. G2 had a bias pot to adjust the gain. Drain load was 2.2k and the source R was 560r. Output was taken from the drain via a 0.1 cap and in this case fed a coupling coil which could be attached to the end of a portable radio, coupling by transformer action. To help things along, a small feedback winding on the rod was fed via a 0.1uf from the source. In use, once the required station was tuned and peaked, the gain pot would be advanced to just short of oscillation. The effect was dramatic and the tuning became very sharp. At the time I originally built it, there were a couple of naughty music stations that were pretty poor copy here in Cheshire, but with this thing adjusted for maximum smoke they came in like the proverbial ton of bricks. September 1995, don't know if it's online anywhere. __________________ Andy G1HBE.

25th Jul 2016, 8:35 pm	#5
mike g3zii Retired Dormant Member Join Date: Jun 2015 Location: Southport, Lancs. UK. Posts: 31	Re: Set-top Aerial This is it. I developed this from a unit I made to receive the 80 meter ham band without all the hash from switch mode rubbish and digi-junk, then I thought I'd try it on the broadcast bands. it has worked out very well. it runs on 6 AA batts at less than 3mA including the LED. it's a ferrite rod aerial tuned across 160-1700 Khz amplified by a bf964 dual gate fet. the signal is choke capacitor coupled out to the radio on a screened lead.it's good with my tired old wartime civvy set which usually needs a 50 foot outside wire to get it to do much. it lives in a 5 x 4 inch plastic box. I am just getting the paperwork finished then I may start producing them in kit form,also ready built. Attached Thumbnails