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J Richardson
09-12-2010, 02:41 PM
Hi,

In my quest to complete my shop before winter, I need to set up an antenna and ground for some shortwave listening. Before sheeting the walls, I ran a wire outside for a future longwire connection. But, as I'm getting closer to sheeting the ceiling, I was wondering if I couldn't staple my antenna to the top of the roof trusses, and not have to worry about snow, ice etc. Anyone have some basic lengths and/or configuations that might work? The garage is 24x32, with the 24 foot length being the same as the truss peak. Also, does the wire have to be bare, or can I pick up a spool of #14 and use that? Haven't done this since I was a kid, and the memory is a little rusty.

Thanks,
John

darryl
09-12-2010, 04:17 PM
The wire does not have to be bare, except for where you make a connection to it. Where you run the wire is going to make a lot of difference. You would very likely find that if you run it around inside the shop, it will pick up so much interference that it would be a wasted effort. Ideally, you run it away from power lines, and of course you orient it for best reception. This is my opinion only, but I think that if you run it around inside the building, or up on the rafters, etc, you won't be happy with the results.

JoeLee
09-12-2010, 04:36 PM
Run the antenna outside and as far away from the shop as possible, and use good feed line with about 99.9% shielding, not the crap shack stuff with two strands of wire that they call braid.

Antennas in close prox. to machines, phase converters, flourescent lights, etc. will result in poor reception and a lot of noise.

JL.....................

The Artful Bodger
09-12-2010, 04:38 PM
I would put a wire in the roof space like you say, it will probably work unless you have a metal roof in which case it might work.

There are huge books on the theory of antennas and no doubt there are people on here who have read them all but in my experience just putting a wire up is always better than nothing!

If the roof space does not give satisfaction you can think of the outside wire then.

MichaelP
09-12-2010, 05:07 PM
As long as you're not going to transmit, you can use a random length of wire in your attic. In general, the longer your wire will be, the better reception you can expect (for both, radio stations and interferences that, as mentioned above, you'll have a plenty of).

Running a long wire (or any other antenna) outside will, generally, provide a much better reception and less RFI. But then you'll need to deal with anchor points, isolators, weather elements, etc.

What you can do is install an attic antenna for now and prepare whatever you'll need for an external one if you ever want it. When I was involved in shortwave radio operation, I simply put a large diameter PVC pipe through the wall and ran all my coaxial cables and ground through the pipe. So I really didn't need any special preparation during my home construction.

darryl
09-12-2010, 05:07 PM
I suppose it can boil down to 'if it works to your satisfaction, use it'. No harm in running the wire inside as you wondered about. If it doesn't work well enough, just don't use it.

What kind of roof will there be? If metal, it's quite possible that a simple connection to the roof will bring in a good enough signal. Not saying it will work, just that it might. In any event, you would be well advised to look into lightning protection. Wouldn't be so bad to lose a radio to lightning, but if you have invited lightning into your shop by some means, such as an outside antenna, it could be you getting the jolt-

wb2vsj
09-12-2010, 08:14 PM
Run the antenna outside and as far away from the shop as possible, and use good feed line with about 99.9% shielding, not the crap shack stuff with two strands of wire that they call braid.

Antennas in close prox. to machines, phase converters, flourescent lights, etc. will result in poor reception and a lot of noise.

JL.....................

Agreed! Get it as far away from the shop as possible if you can. The attic is just as bad. You won't believe the amount of electrical noise a house/shop can generate. I've been a Ham Radio operator for 30+ years and have experienced i.e. (been plagued by) all type sof man-made noise. Just try and tell the neighbor that his electric blanket is screwing up your reception ;)

Out of curiosity, what type of SW receiver will you be using? I have an old Hallicrafters SX-62A in my shop that I use.

Walt
WB2VSJ
Apex, NC

J Tiers
09-12-2010, 10:05 PM
With the electrical noise in the shop, I bet your inside antenna won't work well unless the radio is rather selective, and the EMI is minimal.

However, on a functional basis, attic antennas are fine.

In fact, our house, which was built in 1934, has two outlets which are FOR radios, one downstairs and one up...... In each, one half is a 120V 2 prong, and the other is a connection to antenna and ground. NOT via a standard plug, of course, something between a banana plug and a "phono tip".

I do have some shortwave radios, but none is in a place to use the built-in plugs. The builders evidently had different ideas of interior layout than we do.

The Artful Bodger
09-12-2010, 10:28 PM
It is hard to predict the electrical noise in the shop without knowing more about what will be in there.

You can be assured that the radio will jump out of its skin if there is any welding going on and maybe if using any high speed brushed motors such as drills and routers but even most of these are electrically quiet.

I would not expect much noise from anything with a synchronous motor even if you are running off a rotary phase converter.

Modern electronics including VFDs should be electrically quiet.

J Tiers
09-12-2010, 10:30 PM
Modern electronics including VFDs should be electrically quiet.

And they are.... "quiet" is defined as "less than "X" amount of noise......... The problem is that "X" amount is typically a lot bigger than the signal from someplace in South America, etc, etc.

JoeLee
09-12-2010, 10:52 PM
Agreed! Get it as far away from the shop as possible if you can. The attic is just as bad. You won't believe the amount of electrical noise a house/shop can generate. I've been a Ham Radio operator for 30+ years and have experienced i.e. (been plagued by) all type sof man-made noise. Just try and tell the neighbor that his electric blanket is screwing up your reception ;)

Out of curiosity, what type of SW receiver will you be using? I have an old Hallicrafters SX-62A in my shop that I use.

Walt
WB2VSJ
Apex, NC

See..... it takes another ham to agree with me. Believe us when we tell you..... we are speaking from experience.

JL.............

dp
09-12-2010, 11:41 PM
A decent ground level antenna can be built from a large glass 7-Up bottle (Coke/Pepsi will work too :) ) and three or four 10' sections of TV mast stacked on the neck of the pop bottle. Use nylon line clamped midway up the topmost section. Use a good stainless hose clamp. Tie off the lines where ever convenient.

For transmitting you'd use a good neon sign insulated HV wire, but anything will work for receiving. Run what ever wire you have to your receiver.

And just for kicks, build one of these to tune it: http://www.qrpkits.com/altoidslongwire.html. It is feed with 50 ohm coax cable.

A coupler like this needs a good ground at the coupler. If you don't use a couple you'll need a good ground at the receiver and that's usually more difficult. Long wire antenna can have pretty low impedance and anything that creates impedance in the ground circuit is going to create noise.

Spark arrestors are a good idea if you're in an area prone to lightning. This page has some useful ideas:

http://www.techlib.com/electronics/antennas.html

Dragons_fire
09-12-2010, 11:59 PM
unless youre using earphones, youre not going to be able to hear the radio over any of the tools anyways. It they have a big enough electric motor on them to cause enough interference, they are going to be loud enough that you wont be able to hear it.

The Artful Bodger
09-13-2010, 12:28 AM
There are Hams, SWLs and people who just like to listen to some shortwave broadcaster beaming to their region.

The opening post did not give the impression of being from a Ham or SWL which leaves the shortwave broadcast listener.

My advice remains the same, put a wire in the roof space and see how it goes.

J Richardson
09-13-2010, 05:15 AM
Hi,

Thanks for the replies. I think I'll run a wire outside. Sounds like the best way to go. I've got an old Hallicrafters American five tube that I need to finish recapping. Also need to get my childhood Stewart Warner up and going again. Neither radio is much, but it's something to listen to. Love the sight and smell of tubes in the dark!

John

Your Old Dog
09-13-2010, 07:46 AM
unless youre using earphones, youre not going to be able to hear the radio over any of the tools anyways. It they have a big enough electric motor on them to cause enough interference, they are going to be loud enough that you wont be able to hear it.

He's right. I have an Icom IC 7000 transceiver and a 2 meter for around town in my shop. I have no problems with interference but then again, I absolutely never run the mill, lathe or shaper while trying to listen to ANY radio or TV as it's just too loud. If the machinery did bother the radio I still wouldn't hear it for all the machine noise. The radio is nice company when setting up for other operations.

Buy yourself something like magnet wire, run it around you trusses, sheetrock over it and see how it plays. My guess is it will fit your needs easily unless of course you are working for 5 Band DXCC :D

J Tiers
09-13-2010, 08:17 AM
HEARING the radio?

if you can hear the AM or FM, you can hear the SW.... The question is WHAT will you hear...

There are hundreds of areas around town here where when you get near AC lines of any sort, even a local full power clear channel AM radio station is completely blanked out. Typically by a roaring noise, but a few have a really odd noise that sounds more like sound effects from a bad SF movie.

if all you have is regular induction motors and no VFD, you probably won't have much local problem, if the AC is clean coming in.

Add VFDs, etc, etc, and the trouble starts.

High voltage lines over a mile from the Chrysler plant (oops, sorry, the FIAT plant, now closed) gave off enough noise to totally destroy AM reception. You can figure that plant was full of drives, welders, and every other sort of industrial noisemaker.

SW starts above AM, and many things might be muted by 10 or 15 mHz, but not always. Switching devices have a LOT of harmonics.