[MRCA] static discharge reel for antenna

Sun Oct 13 18:17:07 EDT 2013

Nice TCS set up! You friend is very lucky.

Here is a picture of the kind of reel I am talking about. You can see the wire is insulated and the inside end of the wire is accessible. 
http://ecx.images-amazon.com/images/I/41Yl4ZZAkjL._SL500_AA300_.jpg

if that image doesn't come through, search amazon for B00BLQZUFW  and the unit will come up (disregard the cost, I would have to have my head examined to may anything like that)

Yes, I know of that fishing wire reel AT-984. But I like the idea of having it automatically retract as I lower the mast.  

Seems like the consensus is to cut down the 50' to the length and not have anything extra. Then insulate and go

Thanks everyone

73 Eugene W2HX

From: Tim [mailto:timsamm at gmail.com] 
Sent: Sunday, October 13, 2013 2:21 PM
To: W2HX
Cc: mrca at mailman.qth.net
Subject: Re: [MRCA] static discharge reel for antenna

Hi Eugene - Not sure I can entirely visualize what that "static discharge reel" might look like rigged to a mast - the ones used in fueling aircraft seem to be pretty substantial...
My buddy did something similar with a plastic fly-fishing reel and some 24 gauge (?) wire rigged as a horizontal "NVIS" lashup while fixed-portable camping.  The vehicle end is held up by a short PVC pipe mast "suction cupped" to the rear window.  The quarter wave wire then runs off to a nearby tree for support. He also runs a quarter wave ground wire laying on the ground to "ground" the system.  
He is running either a TCS or GRC-9 while camping.  It works great.  He is not a "DX-er" so he has no need for a vertical radiator.  Take a look at some Pix I took of his setup on a recent campout:
http://www.n6cc.com/temporary-posts
Also, the little "long wire" antenna used with the PRC-25/PRC-77, (AT-984A/G),  is also a metallic fly fishing reel with uninsulated stranded wire (150') for VHF use.  It should also work great on HF if reeled out to the appropriate length. The unused coiled-up wire should short all the turns together and not act as an inductance... Making a homebrew version of this antenna is essentially what my buddy did.  For zero - a couple hundred miles out, the low horizontal wire seems to be optimum and works great....

Improvise, adapt overcome!
73, Tim

On Sun, Oct 13, 2013 at 10:46 AM, W2HX <w2hx at w2hx.com> wrote:
Hi folks.

BACKGROUND
I have an 8m mast on the back of my 72 land rover. When I deploy, I either run a wire up it for a vertical (which seems to work fine) or hang a dipole on it as an inverted V.  I am always trying to make deployment as simplified as possible. So I was thinking of using one of these retractable reels used for static discharge in situations like fueling etc.  Basically it's like the old laundry line in the back yard. Spring loaded, retractable. The idea would be to mount it on the land rover and have the cable attached to the top of the mast. Then, all I need to do is raise and lower the mast and the wire is already in place.

There seem to be two main types of these reels that I can see. One type uses un-insulated wire and uses the body of the reel to complete the connection to ground. Meaning the paint is removed from the mounting points of the reel to make electrical connection to something metal as ground.  The second type uses an insulated cable and the internal end of the cable connects to the outside of the reel, making the internal end accessible. In turn, again, the reel is grounded.

In the first case, I would need to mount the reel in such a way that it is insulated from the body of the vehicle so that I can use it as an antenna radiator. This will be some small challenge to accomplish.  The base of the reel body, insulated from the vehicle body, would then connect to the output of the antenna coupler.

In the second case, when the cable emerges from the reel, I was thinking of putting on a single-conductor connector (like a single power pole) when the cable is fully reeled out, I can then connect a wire from the antenna tuner to this power pole.  By disconnecting the internal end from the reel and connecting to the power pole, the reel and reel housing are no longer part of the circuit and can mount on the body as needed.

QUESTION:
The second type of reel (with insulated cable) seems to come in 50-foot lengths. This means that about 25 feet will remain on the reel in a loop about 3-4 inches in diameter. I am worried that this will create an RF choke and reduce the performance of the radiator. Or, it might make some kind of base loading, I really don't know.

Of course an alternative would be to cut down the cable to 25-26 feet or so, but I was wondering if anyone had thoughts about the effect of having this 25' coiled before the vertical radiator.

Thanks for the bandwidth of a very wide band email!

73 Eugene W2HX

______________________________________________________________
MRCA mailing list
Home: http://mailman.qth.net/mailman/listinfo/mrca
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:MRCA at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html