Leaky feeders in the workshop. - UK Vintage Radio Repair and Restoration Discussion Forum

Biggles · 17th May 2018, 8:30 pm

While working on FM sets with those small internal aerials I got on thinking about whether there would be any benefit in routing my outdoor FM antenna into some sort of leaky feeder or rebroadcast antenna onto the workbench. I did successfully do this to improve the comms inside a building years ago for our data system at work and that simply used an outdoor antenna connected through a wideband amp to another dipole mounted on the ceiling. I wonder if anyone has done any experimenting in this field? It would be perfect for fixing portables on the bench with whip aerials which don't always have an external aerial socket fitted.
Alan.

Hybrid tellies · 18th May 2018, 10:13 am

If there is no FM signals finding there way in from the outside world into you workshop and you have an external FM aerial feeding your distribution amp you could plug a set top rabbit aerial into one of the amp outputs which should work. You would have to be careful to keep the radiating levels low to prevent any interference outside the confines of your workshop.

G6Tanuki · 18th May 2018, 8:06 pm

Rather than a leaky-feeder, I'd go the 'passive repeater' path: connect the incoming coax to a half-wave dipole inside your workshop.

[In the past I did this to deliver FM radio-broadcasts to the inside of a shipping-container: OK, I also interposed a +16dB gain 'distribution amplifier' in the signal-path to help out a bit]

17th May 2018, 8:30 pm	#1
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Leaky feeders in the workshop. While working on FM sets with those small internal aerials I got on thinking about whether there would be any benefit in routing my outdoor FM antenna into some sort of leaky feeder or rebroadcast antenna onto the workbench. I did successfully do this to improve the comms inside a building years ago for our data system at work and that simply used an outdoor antenna connected through a wideband amp to another dipole mounted on the ceiling. I wonder if anyone has done any experimenting in this field? It would be perfect for fixing portables on the bench with whip aerials which don't always have an external aerial socket fitted. Alan.

18th May 2018, 10:13 am	#2
Hybrid tellies Nonode Join Date: Jan 2004 Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area. Posts: 2,965	Re: Leaky feeders in the workshop. If there is no FM signals finding there way in from the outside world into you workshop and you have an external FM aerial feeding your distribution amp you could plug a set top rabbit aerial into one of the amp outputs which should work. You would have to be careful to keep the radiating levels low to prevent any interference outside the confines of your workshop. __________________ Simon BVWS member

18th May 2018, 8:06 pm	#3
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,996	Re: Leaky feeders in the workshop. Rather than a leaky-feeder, I'd go the 'passive repeater' path: connect the incoming coax to a half-wave dipole inside your workshop. [In the past I did this to deliver FM radio-broadcasts to the inside of a shipping-container: OK, I also interposed a +16dB gain 'distribution amplifier' in the signal-path to help out a bit]