Antique Radios Forum

This is the temporary home of the Antique Radio Forums while a new server to host it is being found. You will have to register here to post. Please Note: None of these topics will be preserved when the original forums are back.
 
HomeCalendarFAQSearchMemberlistUsergroupsRegisterLog in

Share | 
 

 Bad Indoor Antenna Idea?

View previous topic View next topic Go down 
AuthorMessage
philconerd



Posts : 4
Join date : 2010-10-16
Location : Retiring in N. Minnesota

PostSubject: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 9:03 am

My workbench is in the basement so I have been looking at the duct work for the forced air furnace. Has anyone tried to use the hot air ducts or cold air ducts for an indoor antenna? This would provide about 60 or 70 running feet of indoor antenna. Would it be safe to use for a transformer radio or AC/DC set?

Yesterday I measured the AC Voltage from the duct to the grounded pin in the outlet and read 0 volts. But when I measured AC Voltage to the chassis of my Marantz stereo receiver I read 90 Volts. So maybe it isn't a good idea to try the ducts for an antenna?

G.




Back to top Go down
View user profile
Alan Douglas



Posts : 62
Join date : 2010-10-13

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 9:37 am

I would expect that electrical codes require ductwork to be bonded to ground?
Back to top Go down
View user profile
pixellany



Posts : 58
Join date : 2010-10-12

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 9:54 am

Regardless of whether an antenna is inside or outside, don't you want it to be as high as possible above grade? If it has to be inside, I'd say put it high in the attic----far away from the (grounded) ductwork
Back to top Go down
View user profile
jack shirley



Posts : 67
Join date : 2010-10-12
Location : SE USA

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 9:55 am

They certainly do nowadays with a caveat of 'only if they pass within 6 (or is it 12) inches of any other conductor or grounded object' which is almost always the case.

The voltage you're reading from the Marantz to duct or ground may be the normal ac leakage from an AC bypass capacitor.

At any rate, the ductwork probably wouldn't make a very good antenna.
Back to top Go down
View user profile
k9uwa



Posts : 18
Join date : 2010-10-13

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 10:03 am

pixellany wrote:
Regardless of whether an antenna is inside or outside, don't you want it to be as high as possible above grade? If it has to be inside, I'd say put it high in the attic----far away from the (grounded) ductwork

not necessarily. Very Low Noise Receiving Antennas called Beverages. Not the type you drink. Are Long LOW to ground wires. Some are referred to as BOG .. thats a Beverage ON GROUND. Simply a Long Wire that is LAYING ON THE GROUND. Made of course from INSULATED WIRE. The idea here is that it is a VERY LOW NOISE antenna. Yes the signals are down perhaps from one that is up in the air. But the NOISE is down farther than the signal level. Making it a BETTER antenna than a higher one in some circumstances.

Try It you just might be suprised. Put out about 300 feet of insulated wire just laying on top of the ground and attach it to your old radio. Then listen at night to it and switch between it and another higher shorter antenna. You may well be amazed. Yes you will have to turn up the volume control or add a Pre-Amp but you will hear stuff that you didn't know existed with that higher short antenna.

Then do the same thing with a 400 foot wire thats 3 feet above ground. More amazement coming up. Most of us are forced to put these antennas up around 8 feet high. This is to keep people and Deer.. the type with Antlers on them from knocking the antennas down when walking about in the woods. Or the Snowmobilers from hanging themselves in the fields.

John k9uwa
Back to top Go down
View user profile
gvel

avatar

Posts : 14
Join date : 2010-10-12
Age : 61
Location : Howell, MI

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 10:27 am

Don't know about safety issues here, but I've done this in the past. It worked incredibly well! Too well, as a matter of fact, I could barely control the volume - on a TRF receiver.

I'm assuming this will be just for testing? If so, tack up a hunk of wire, and be done with it.

I've used a used a long random wire, in the basement, for amateur radio transmitting. Shady indeed, but I was on the air!



Back to top Go down
View user profile
Chas

avatar

Posts : 33
Join date : 2010-10-12
Age : 70
Location : S. Dartmouth MA 02748-1225 ------------ Avatar: Uncle Tony's Shack

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 11:35 am

I use the ductwork in my home as an antenna. Works better than no antenna at all. Not as good as a 2' tuned diamond loop. I also use the telephone line, the shield of the coax on the household MATV system and the electrical ground at an outlet.

Yes, I get noise, some beeps and buzzes from the various digital devices around the house. For serious listening I have an outdoor long wire and an 8" ground rod.

The most serious noise issue is when a powerline lightening arrestor or a street light fails. I track down the pole number and turn it in to be repaired...
Back to top Go down
View user profile
philsoldradios

avatar

Posts : 16
Join date : 2010-10-18

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 11:46 am

Have you tried simply stringing up a long wire in the basement? It might work better than you expect. There are so many variables . . . .

Worth a three-minute experiment, anyhow.

Phil Nelson
Back to top Go down
View user profile http://antiqueradio.org/index.html
philconerd



Posts : 4
Join date : 2010-10-16
Location : Retiring in N. Minnesota

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 12:11 pm

Okay, thanks all for the opinions.

I was just curious about using the duct work sometime. I actually do have a 60 FT longwire 10 Ft high outside for the radios that I keep in the basement. It even helps the signal strength for FM radios when I lay the antenna wire near the power cords.

I will try laying out a longwire on the ground and run it out into the woods. I must do that before the snow flies here. I am anxious to give it a try.

G.
Back to top Go down
View user profile
radiotechnician



Posts : 35
Join date : 2010-10-12

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 12:41 pm

If you wind a coil, lets say 1 1/2 dia. x 6" L with as many turns in one layer that will
fit, say about 100 turns, and use that connected between the duct and a solid metal water pipe
as a grounding drain , the duct then should be safe for an antenna.

In the past a favorite antenna was the metal fingerstop on a dial telephone especially if you house was a long way from the pole. (Just think how good a classic dial phone would look next to that 1937 radio and the kids packing a textmessaging cellphone wouldn't know how to use it!)
Back to top Go down
View user profile
burnt fingers



Posts : 70
Join date : 2010-10-12
Location : New Hampshire

PostSubject: Re: Bad Indoor Antenna Idea?   Thu Oct 21, 2010 3:21 pm

Give it a try, at least it might make a decent test antenna.

I have a 70' wire antenna in the basement tacked to the floor joists above in a U shape that works much better than expected. I run a twisted pair down lead to the work bench with the extra wire clamped to the copper water pipes which are also bonded to the mains panel and earth ground. It cant compete with the outdoor antennas and picks up house crud but its better than a finger on the antenna screw or a piece of hookup wire.

Carl
Back to top Go down
View user profile
Sponsored content




PostSubject: Re: Bad Indoor Antenna Idea?   

Back to top Go down
 
Bad Indoor Antenna Idea?
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» Ask bout antenna
» Fallen blood angels army Idea
» Dark Heresy Campaign Idea
» Possible story idea
» Any gameboard idea's

Permissions in this forum:You cannot reply to topics in this forum
Antique Radios Forum :: Antique Radio Forums :: Antique Radio Discussions-
Jump to: