JPC 12 Antenna - Simple Modification
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- Опубліковано 3 кві 2024
- The JPC-12 antenna has proved to be one of the most popular portable HF antennas. It is light and easy to erect and use. But there is one drawback that prevents it from being even more versatile. Peter G3OJV describes the change he mad in order to be able to use the antenna in in other applications. READ THE WARNING BELOW.
The bracket was originally intended as an adaptor to use the antenna with 3/8 inch mag-mount.. The radial terminals were added so that the bracket can be used in ground mounted installations that makes fitting radials easier. Do nit attach anything to the terminals when used as a mag adaptot.
Buy Your JPC-12 antenna direct from UK Importers.
www.hamradiostore.co.uk/jpc-1... - Наука та технологія
Hey Peter, many thanks for sharing your experiences using JPC-12. Much appreciated. (And the wind muff actually worked like a charm. 👍) But being a guy from continental Europe, let me assure you: there's absolutely nothing wrong with a metric thread. 😉
Ha ha - yes some of us oldies still struggle ?
Great idea for a mounting bracket
Thanks Peter, good video. 🙂
I know that SAE thread standard is popular here in the USA, but I prefer metric.
Table hole quick thinking Peter, Thanks
I love mine and this is great way to get more out of it! Id have liked to have been able to fit my MFJ1979 into the coil and see what that would do. Thanks for the ‘ how to’! 💐
Hi Matt
I was just going to say the same, you would not connect radials on this side of the antenna,😂😂😮
I got one of these of eBay for £60 in used,
Dave 2E0DMB
Hi Peter,
Wouldn't the radials be electrically connected to the hot side of the antenna, rather than the ground?
Does that matter? I always assumed they had to be electrically isolated.
Cheers,
Matt
M0PTO
Radials are always connected to the earth side of the antenna. But you are right, when the bracket is used on a mobile mount, the bracket is live and forms part pf the radiating element.
Same weather in New Jersey, USA.
very informative!!!
Plan to purchase one for our POTA activities.
73 DV1K
Nice set up peter.
20m to the uk from zl is good on dark here. Have a nice weekend. 73 zl3xdj
Hi Brian, thanks for that. I worked VK two nights ago on 40m. Must send you an email and catch up. 73 Peter.
@@watersstanton vk on 40m, well done. 40m not open here for me, but 20m along the greyline is good to the uk, even had uk on ssb last night.
Here there is a big difference between vk and zl south island on 40m.
Iam recently around 14.030 - 14035.
73.
I used it on a boat a small fishing boat while it was raining and I made over 180 contacts using 5watts with a KX3
Well done.
What core are you using on the feedline? Do you have a part number? Thanks! Great video.
I would weld it together and it would be much smother design.
Hi Peter. I was looking forward to this episode about this antenna. I have questions. How many and what length do you recommend the radials be? Is it mandatory to use all 4 aluminum tubes (vibrators)? Can an antenna work without them? I have a longer telescope, does that mean I can work on 5 and 3.5 and 1.8 MHz? Or can I use the original one for these bands? Greetings, 73! LZ1INP
I think I covered most of this two videos ago. I use 3m radials nut not critical. . You can remove tubes. You need a very long whip to get down to 80m. Probably not practical.
Very good but what are the specs for the ferite ring please and do you sell them thanks
I always use 240-43 ferrite rings
I solved for this by simply getting a 3/8”-10mm adapter
Decent ones are not that easy to find
@@watersstanton A decent thread reduction adapter should be K&M 21980 (from female 3/8" to male M10), together with a male 3/8" to male 3/8" adapter (like Manfrotto 125), both are available from Thomann, Sweetwater, Canford as well as probably other music stores.
@@arndgronenberg won't do the trick! Antennas have 3/8'' UNF and not 3/8'' UNC. This won't fit!
Has anyone come up with a modification to make the JP-12 (or JPC-7) work on 80 meters? Maybe another loading coil or a longer whip?
*73 de AF6AS*
Yes!
What is the difference between the pac12 and the jpc12 ?
Hope this link helps peter 73s M7DXT
Can't see the link? Try again.
Mine sits in soil in a hole in my concrete back yard where a shrub used to be. However the radials rest on concrete, is that ok?
Yes radials on concrete work.
Question: (new tech here) but what size toroid chokes are the best to keep in hand?
Love your content btw
73
N0CKL
I use 240-43 type.
@@watersstanton thank you
What?!?!
"One of the most obvious problems is that this antenna has got a 10mm thread."
One of the most obvious problems with almost any (US-made) antenna is this awkward UNF thread. Outside of the US you simply cannot get any spare parts (nuts, bolts, screws) using this thread. You have to make all of these by your own. I have the possibility to do that. Most Hams in Europe and in the rest of the world cannot do this and live in a pure metric world (meters, millimeters...) and have a really big problem with these UNF antenna threads.
The JPC-12 antenna having metric M10 threads is one of the biggest plus-points of this antenna.
I mis the point... I think . PD4TZ
Peter the radials won't work off that bracket
I probably confused some viewers. The backer is used at the base if the antenna when ground mounted abd radials connected to it work fine. On the mag mount it is used as an adaptor and the becomes part of the radiator. in that configuration the radial terminals are not to be used.
Just weld the 10mm nut on top of the 3/8 bolt?
So why did they use 3/8 x 20 threads instead of the fairly standard 3/8 x 24 threads on all their stuff. Now it is incompatible with all my other coils and whips. Very stupid ... cant even use it on my mag mounts ... sending it back for refund as all my mounts are 3/8 x 24 thread.