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Par EndFedz MTR 20/30/40 SMA Cap

I’ve got a Par EndFedz 20/30/40. It uses a shorting SMA cap to close a circuit and operate on 20/40. It works on 30M with the cap removed.

My goodness it is tough to keep up with that cap in the field. The best I’ve come up with is to drop it into a pill bottle when I remove it.

There are cheap chain-attached dust caps, which nicely cover the connector when using the antenna on 30. Non-chain shorting caps are available for $3, but chain-attached shorting caps are $25-35.

I’m thinking of using a male-to-male gender mender, filling one end with solder, and putting a brightly colored wire tie around the middle, to make it easier to find when I drop it.

Anyone have a better idea for how to either tether the shorting cap or make it easier to find among the leaves on a summit?
73 DE K4KPK / Kevin

Piece of string/nylon cord glued to the shorting cap and the other end attached to the antenna. You can’t(*) loose the cap then.

  • for various definitions of can’t
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Kevin,

A suggestion.
Look out lengths of RG174 at hamfests with a connector attached. Cut the cable down to 30 mm and carefully remove some of the outer and insulation. Solder the braid and centre conductor to make a short. Slip a coloured piece of heat shrink over the coax tail. You can put a thin cord under the heat shrink. Then apply hot air and shrink. You can tie the new short to your antenna using the cord. Make a spare and keep in your rucksack, just in case

73
Ron
VK3AFW.

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I’ve got the same antenna. Best I’ve come up with is putting the 30m cap in my pocket as soon as I take it off and making sure it’s back on when I wind up the antenna.

BTW, when you trimmed the wire, how much did you take off? I’ve not been able to get my 40m SWR below 1.9

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Matt, I was going to write this but you’ve done it for me.

Trying not to lose small but valuable items at the summit can be a nightmare [I’m sure this could be a reflector topic in its own right]. More than twice my precious [and now no longer replaceable] Palm Pico twin paddle key has fallen down between a gap in the summit rocks whilst taking out of its storage bag.

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I checked the description of this EndFedz® EFT-MTR antenna at the Vibroflex page and read the operational manual.

What I really don’t understand is why the product manager of this antenna has chosen to use an SMA-connector as radiator link.

In my opinion, SMA-connectors in the outdoors are not that robust (water, dust, insects, …) and probably not the best choice in winter when fingers are frozen.

Also, the weight of this “link holder” that looks like a coil makes the radiator in some configuration most likely unnecessary sagging.

Further, why is the red plastic pigtail of this SMA connector by default not attached to the “link holder”?

I think most simple home-brew link solutions do better, but maybe I miss something…

73 Stephan

Various end-fed antennas from Par EndFedZ have been on the market since approx. 2003, initially only monoband antennas.

The reservations made are absolutely appropriate and they appear again and again in the various forums from time to time, e.g. also here

The self-construction of such a simple linked EFHW is really a very simple project.

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I own the same antenna, and have experienced the (inevitable–?) loss of the cap.

I like VK3AFW’s solution, but what I did (after creating my own shorted SMA connector) is along the lines of MM0FMF’s recommendation. I used some very strong fishing line wrapped around the connector’s stem and super/krazy-glued into place. the other end is glued and taped to a small circular velcro/hook and loop pad, with the companion pad attached to the gray oblong. When I remove the SMA cap, it just dangles from the velcro closure. There is enough slack in the fish line to place the cap in position for 20/40.

I agree that putting such small items in pockets isn’t really effective; I’ve lost more gear that way! And in winter it can be a real pain trying to do something like that with gloves on.

Of course, there is another solution, one that is ideal for the indolent – if you have a good tuner, just leave the SMA connector in place and use the tuner on 30M. I confess to committing that sin quite frequently. ;-).

73 Paula k9ir

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This was my default HF antenna for the last 3 years (then sold by LNR Precision) and occasionally I too would let the great internal ATU in my KX2 do the business for 30m rather than jump up and get the 30m stub off [which was often higher than I could reach].

In recent months my default antenna is a Chameleon MPAS Lite vertical so now I can just sit there and press the rig’s ATU button to switch between bands. And with gloves on it’s much less fiddly to put up and take down in cold weather.

Sorry for the bandwidth, this is just an indication that a link to a post from October 2015 was added in my previous post.

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HB9BCB - Thank you for the reference to the original story. I hadn’t realized the blob is only a link. That’s a big link!

If it’s just a link, I’ll bet I can find a smaller egg and build my own with an SPST switch instead of the SMA-short link despite my claim “I don’t do builds well.”

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Thanks Heinz for the link to the old discussion that dates back when I didn’t know about SOTA.

My critics was not about the antenna performance (even when assuming that a mediocre coupler was used), but about the akward design of the 30m link.

This could be used to show an example of over-engineering and reminds me a bit about the old tree swing cartoon :wink:

73 Stephan

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