The more I get into reading stuff here the more I see people having good success with ultra compact loaded verticals. I’m thinking of getting a Commet HFJ350 due to how compact it is and pairing this with a tuner and my truSDX for a low-cost solution for mountain top CW. However, I would like to get some feedback from folks who have used this antenna before I purchase. I fully understand how limiting this antenna will be, as such I am only hoping for regional CW and maybe FT8 contacts with it.
I’m just looking to greatly simplify and downsize my portable kit into something that is a single clutch sized case that I can throw in a pack any time I head out.
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This is one of many versions of the “built-in-china” designs which uses a wire link to select different parts of the coil.
This (IMHO) is NOT a good approach.
The problem is that when you set up. you will set it up on different ground surfaces, with different objects around the antenna that can affect it. what happens if you want to operate at the top end of the band and then the bottom - OK, you can try to tune using out the difference by adjusting the length of the whip but for the most radiation, you want to leave that whip fully extended (except perhaps on 6 metres).
With just half a dozen position option taps on the loading coil, you don’t have any “fine-tuning”.
For a few euros more you are better off going with the Komunica HF-PRO2-PLUS-T from the Spanish Komunica Power company. As of 2023, you can also buy knock-off copies of this antenna from MFJ and others as the design is being copied now. The Knock-offs cost around €100 the original around €150 but the knock-offs come usually without the 80 metre plug-in extender coil and so only cover 40-6m.
This antenna does not cover 160 metres. If you need that, keep searching but my point is an antenna design with a slider adjustable coil will give you fine tuning on a summit and of course, no ATU is needed.
I’ve had my HF-PRO2 for over 5 years now and am very happy with it. I converted a photo tripod to act as its mount and added radials to it but Komunica also sells a tripod kit for the HF-PRO2 if you don’t feel confident in building your own. I have worked, literally around the world from Germany, Austria and Cyprus into VK & ZL using 20 watts of SSB and this antenna.
Good luck with your choice but my experience with the antenna with a wire shorting link has never been good.
Kommunica Power HF-PRO-2-PLUS-T Antenne 3.5-30 + 40/50/70/144 MHz (wimo.com)
I’ve tried to find a supplier in the US of the original Komunica antenna but it seems only the copies are available and the Komunica one is only sold within Europe.
73 Ed.
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Thank you for the input. I’m certainly not expecting a wonder antenna because you know… physics… It is always good to hear that micro antennas do indeed work. And I have no interest in 160M, even 80M will likely not be used. I will primarily be using 20 and 30. I may occasionally venture down to 40.
Besides the tuning challenges, are there any other reasons you do not like tapped coil style antennas?
I will also say one reason I am considering the Commet is it is made in Japan, which should mean higher quality than the Chinese and Taiwanese versions. This in my mind will be critical for something so compromised as I’m sure poor materials and workmanship will quickly compound to make it unusable. Finally, fine tuning is supposedly accomplished by adjusting whip height.
Is it made in Japan? Or is it made somewhere in Asia for Comet, a Japanese company ?
Don’t forget Apple products are made in China and they’re wonderful shiny things we all covet!
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All of the information I have seen states it is indeed made in Japan.
Also, I will say, just because something is made in China certainly doesn’t mean by default it will not be quality.
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I recently posted on this antenna:
I’ve only used it a couple of times, but it did match easily when operating hand held from the KX2 with a short trailing ground wire.
My favourite antenna for HF quick activations would be the Diamond RHM8B. The reason is that it always uses the fully extended telescopic whip and is matched by tromboning the sliding loading coil. The Comet HFJ 350 is more compact but needs a bit more futzing to choose the correct tap and adjust the telescopic whip (which is further away than you can reach when you are holding the KX2).
Glenn VK3YY.
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I have both, the Commet HFJ350 and Diamond RHM8B and they work. I have crossed many times the Pacific Ocean and I did a couple of S2S with the US with these ¨toys¨
I think that the secret is the set of radials. Tuning is a little tricky but I found I can tune it easier by using more radials. In my case I use 10 radials of 5 meters each.
73, JP3PPL
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Works for me. It’s a compromise antenna
Follow the instructions and use the counterpoise to be a few feet off the ground
Fits in a vest pocket
Pack a 9:1 balun as well and use the counterpoise wire at 29 ft with your tuner as a back up
Of course the short length stinks on 40m but on the other bands the signals are good
I mount it on a Delkin carbon fiber tripod to good effect
John VE3IPS
Better results with 10 -20 watts on SSB but on CW lower power is fine
I put the 160m and 80m coils in storage. It will work but the efficiency is pretty low
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Just another comment on the Comet HF350J. On 20m, the antenna resonates with a disappointingly small telescopic antenna length. I think it was 75cm from memory. I found that if you shorted out the second from the top and third from the top taps, it takes enough inductance out so that on 20m it resonates with 122cm. With such a compromised antenna, every bit of metal in the air should help.
Cheers,
Glenn VK3YY.
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for a stingy but good carry case for the HFJ350, I used a spanner bag from a seconds tool shop (Kincrome). It cost $2.
Glenn VK3YY
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For my Komunica HF-PRO2-PLUS-T antenna, I use a plastic bag from a packet of bake-at-home bread rolls. Cost me nothing. Now that’s stingy!
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After some tries with different short vertical antennas I ended up using a MC-750…. length approx. 5 m
Short antennas did not perform well. At least not in the combination with low power. However, many sets of verticals with coils have limitations as soon as it gets very wet or very cold.
This one works well from 30m to 10m without the added coil together with KX2. The lengths for different bands are marked on the telescopic part.
If it gets very wet, it will get wet in the radial connector part… and can produce problems…. however for normal weather it will perform good…
Had only once the above mentioned problems…
As it uses grounded radials, there is no need for quarter lambda length radials…
73
Ingo
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I use this mc-750 antenna and it works great
It’s a quarter wave on 20m and up and 1/8 on 40m
Beats a 4 ft whip
Beats the super antenna mp-1
John ve3ips
I initially extended the MP1 with a 5m MFJ whip. It performed much better than the original version. But there where problems with the freezing coil in winter time. I shouldnt activate in winter storms 
Also fixing the approx 6m antenna in the soil was a problem…
73
Ingo
Yes adding longer whips improves the performance.
John VE3IPS