[MRCA] static discharge reel for antenna

[Tim]

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
>
>
>
>
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