JPC-12 Quick Deploy Portable HF Antenna With A Neat Carry Bag

My first antenna... I'm beginner. I'm happy with this stuff. With nanoVNA, it's a good way to learn antenna, radials, SWR ... It works well with low power transmitter 20W. A lot of spare parts. I made 20 radials, and now this antenna is perfect for budget.

A mid loaded 1/4 wave element is always more efficient than a base loaded loaded 1/4 wave element, due to current peak being at its feed point. As an example LB Cebik designed and modeled the inverted U horizontal dipole antenna where the outer half of each element dropped vertically, shortening the horizontal length by half. Signal loss was only ~1/2 (0.5) db which in real world usage is unnoticeable. The other 0.5db vertically radiated signal helped to fill in the end nulls inherent in the dipole design. When using a coil that end signal would have been lost in the coil instead of being radiated as RF. Now when you place the coil at the base of a 1/2 length antenna element the majority of your signal will be lost in the base loading coil. This JPC-12 design is an acceptable compromise keeping the loading coil at an easily accessible height while allowing the high current base (most efficient) end of the element to radiate. This is the main reason that mid loaded mobile antennas like the Hustler Radiators, Bug Catchers, Screwdriver... and similar antennas gained so much popularity, their increased efficiency, radiated signal. When the bands are hot even a base loaded antenna will do alright. BUT when the bands are bad or so-so (as in this test) the mid loaded design really shows its stuff (as we saw here)! Folks who use base loaded antennas with hot bands, and rave about them, always go quiet when the bands die and their base loaded antennas show their weakness. I've been licensed since '76 and this cycle ALWAYS repeats, new Majick antennas appear, then disappear when the bands die. This JPC-12 should stick around much longer. An inverted L would be a better option, but not as fast and easy to deploy, and probably not worth the added effort, especially when you'd need one for each band (except 40 / 15m). 73 mike N4ONL

I’ve had one of these for about 6 months now. Takes a while to work out the tuning for bands above 20 metres. Once you have done so it is a fantastic antenna with low SWR on all bands. Great for portable working, up in 5 minutes 😀

These are a great antenna, bought one a while back for portable work. Worked Ferry in Indonesia on 5w from the west of Ireland 😊

I forgot to add that the reason that a centre-loaded vertical is more efficient than a base loaded vertical is simply that the magnitude of the current at the base of a vertical is much higher than in the centre, so I**2 R losses are higher when the coil is placed at the base. This is especially true when the diameter of the conductor in the loading coil is relatively small. If I remember correctly, centre-loading does require slightly more inductance than base loading, but it is more efficient. - Michael VE3WMB

I have one of these and it works pretty well, especially if you add more radial wire! You can also get a 5.2mish whip for it and it can do 20m-6m without the coil.

I had this one for almost 2 years now. Works a treat. The one thing I changed was the connector base, I replaced it with one that's made of aluminium and some kind of delrin, since the original one started to come loose and start twisting.

Have one for more than 1 year and it rocks. great antenna when you learn the tuning setup

Good timing Matt, been researching this type of antenna for portable use whilst in my Campervan. Your turning out some great content recently 👍 Cheers.....Ralph

I've also been very pleased. I've bought another coil and antenna to also make the dipole (jpc-7). Works great. Cheers

I've had the PAC 12 antenna for about 5 years which shares many of the same parts as this version. I'm very happy with the performance.

I've had one for about a year or so now pared with my g90 for QRP work absolutely love it for the simplesity of use and very well built aswell

They also do a nice looking portable shortwave antenna.

I have the JPC- 12 and JPC-7. With the extra coil and other bits you can mix it up with vertical or horizontal / v dipole. Horizontal dipole is very good on 40 mtrs inter G. I keep the coil inline for all bands but will try without one day. You obviously need a tripod for the dipole configuration.

This is a really good antenna. I've been using it for two years. 73!

On a recent trip I discovered that the shortest possible configuration ... putting the totally collapsed telescopic whip directly on the base ... allowed me to tune 2 metres.

Nice review.. 😊 I’ve got one coming ironically too.. had borrowed one and used it on SOTA as well as cable tied to the roof of the van for static mobile and it worked lovely.. Looking forward to getting mine and experimenting.

Long live my good old analog analyzer hi tnx for the video, I love my Antenna.

On the coil there are 2 colors red and yellow, with the whip fully extended, you can quick tune to 20m or 40m, easy!

I have the jpc-7. Only two problems I have with it: sometimes the coils' selector slider gets turned - easy enough to fix, undo the screws, set it straight and tighten; second, I live in a neighborhood with two story houses that are all compactly spaced so I have to put it super high up, I've been mounting it to an telescoping 30ft pool-strainer handle bungie corded to the second story balcony rail of my house to get it up over the common roof line. I like that you can mount the arms of the dipole in many different orientations and can easily string a wire across and have a delta as well. Can even use it as a ground plane but it does not include the ground spike or counter poise wires. I'd really enjoy if you'd do a review of it too, because I'm something of a neophyte and would love a more experienced opinion of it.