Making a shortened 40m Vertical - DX Commander Rapide (old one by request)

[@marciniwaniuk8176]

I've recently built 3 element vertical basing on your Rapide, but on 10m pole. I got coil with 7 turns starting something about 24cm from driven plate. SWR is below 1,2:1 in whole 40m range (7.000-7.200Mhz). And yes 21M band is not perfect but still usable. Thank you for all your work and movies how to model and build antenna. 73 vy SP6MI

[@99corncob]

I used this configuration when I built my Rapide and 40m seems to work fine.

[@TI2GBB]

Thanks for upload the video again Cal!! 73s Ti2GBB Greg 🇨🇷

[@DXCommanderHQ]

No worries!

[@TI2GBB]

@@DXCommanderHQ Cal just one question, is there any way to make a better tune for 21 mhz or this high SWR is by design and cannot be remediate? Thanks .

[@Gw0wvl]

21 MHz is probably high and awkward to tune because there's interaction between the 40 MTR element as it's a loaded 3/4 wave on 21 MHz , So you've got basically two verticals resonant on the same frequency fed at the same time , The 7 MHz loaded element and the 21 MHz element .

[@DXCommanderHQ]

Good answer (!) and NEARLY right BUT when loaded, the harmonic moves (I proved that on the 12.4m development project which waqs fascinating). I can't remember the issue but ikt all works now - thank you!

[@PaoloRendano]

I have a 7m pole and want to try the build before purchasing the DXClassic, what length of radials do you recommend?

[@DXCommanderHQ]

Any will do, from about 2m long and then longer....

[@PerB_M]

You said that The whole screan at The SWR meter is 100KHz, but it reads +/- 100KHz so the screen is 200KHz which makes the result much better. The same for the other bands. The RigExpert shows +/- :-) 73 Per HB9GIM

[@DXCommanderHQ]

Yes, that's cool!

[@stuartmiles1401]

A couple of questions Cal. 1. If you don't have a 6cm loop for the 40m element how is it termianted, do you just tape the bare end to the pole? 2. Why is it necessary to have a discrete 15m element, does the 40m harmonic not work due to the coil?

[@DXCommanderHQ]

Er yes.. Well, it's not exactly "bare" because it's insulated wire and indeed, once you put a coil in a circuit, the harmonics move.

[@martinpe9tig]

Love it ....old by request.......I'm not old i'm matured

[@Marcel55]

Lol (Pa2MKV)

[@gatorman5011]

Did I miss it but how far exactly above the driven plate do you begin the first turn for the 40m coil?

[@DXCommanderHQ]

OK, it's half-way between the driven plate and the first guy point..

[@ylthreezadw3trz575]

Thank you for the tips and ideas👍 Cheers Vy 73/88 Mabuhay!

[@DXCommanderHQ]

No problem 👍

[@kevinkc3onohelijeepworld953]

Will you be playing radio on your holiday ??

[@DXCommanderHQ]

I am 90% certain yes..! 1-week to go.

[@DominicMazoch]

@@DXCommanderHQ Holiday=Vacation across the pond?

[@kevinkc3onohelijeepworld953]

@@DominicMazoch sounds good what part ?