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Good antenna solutions for activator


#1

Due to restrictions of setting up antenna at home and heavy QRM too, i am only QRV as / portable with my K1 and antenna is mainly an end-fed wire that i can swing up in a tree.

But sometimes this wire may not be the best antenna to use so i also have an homemade G5RV-type antenna, and an old matchbox from 60ś working superb and easy to bring with me -in my car yes, but not in a rucksack when on hiking…

I have an SpiderBeam glassfibre mast 12 mtr that have been very useful in some situations to set up the wire or dipole. Here i also need to arrange support for the mast itself, which means more stuff to carry in the bag…

Now, soon as an activator on a summit, specially at treeless heights, I think i need to rethink about solutions for an good working antenna, in combination with a the glassfibre mast, so i would like to hear any ideas or what kind of antenna you are using.

73 / Chris


#2

In reply to SM5KRI:

in combination with a the glassfibre mast, so i would like to hear any
ideas or what kind of antenna you are using.

My loop photos (I have done my activations mostly with FT817ND and only once used ATS3B so far)

I was just checking the model with EZNEC. The gain would improve with higher 6 m or 10 m mast instead of the 4 m fishing rod that I have been using.

Inverted V dipole is popular and has better gain, but the main lobe in my EZNEC models is always straight up. But for NVIS I guess that is ok.

73, Jaakko OH7BF/F5VGL


#3

In reply to SM5KRI:
Hi Chris

I use a double Norcal doublet (88ft long) for 80 upwards on a 10m pole inverted vee fashion.

If your K1 already has the tuner and is a 4 band version with 40 as the lowest band, then a good lightweight option would be a normal Norcal doublet (44ft) on a 6m pole…

http://www.norcalqrp.org/norcaldoublet.htm

Both versions also available here… (no connection, just a satisfied customer)

http://www.sotabeams.co.uk/dipoles.htm

…you just need a lightweight balun.

BTW, looking at propagation predictions for operating from SM summits to the rest of EU, 30m will be as important as 40m (20m occasionally too).

73 Marc G0AZS


#4

In reply to SM5KRI:

Hi Chris

i also in the past “trust the wire” thinking that not any trapped vertical could be better than a dipole or a long wire. So i stuck on “FT817-elecraft T1 tuner-long wire” combo.

But, finally, i gave a try to a Buddistick and i will never look back again :slight_smile: (except in some situations with strong winds, then the wire has less profile).

Budddistick is ligthweigth and you dont need any special supports to raise it (only a ligth photo tripod or anything which elecraft supported small vise can catch).

Perfomance, on 20m at least, is unbelievable. Now i use the “Elecraft KX1 with 4 Watts and internal ATU & budistick antenna” combo on CW and ALWAYS have more than 4 QSO’s in less than half an hour. Its a big difference from these days i had to search for poles to raise the wire in adequate heigth and direction etc…

All the radio load: KX1, key, earphones, 2 Lipo Batteries and Budistick Deluxe Package with a photo tripod weigth less than 2.5 Kg !!

If you have a fellow there who have a budistick ask for a try and i think your portable antenna quest will end :slight_smile:

good luck and lots of fun

best Regards
Panos, SV1COX


#5

In reply to SM5KRI:

Hi Chris

I use the linked dipole. No tuner is required so less to carry and it can be constructed to meet your own band requirements.
See the dimensions and construction methods in these links from John GW4BVE…





Just use the sections you require and disregard the sections you don’t need, it’s a simple calculation. To just use 80/40m you would only require two sections, 957cm for 40m then a link and another 906cm for 80m. Bands are switched by connecting/disconnecting the link.

73 Mike GW0DSP


#6

In reply to SV1COX:

Hi Panos,

I think I have tried to simulate also this kind of short loaded vertical with EZNEC. The gain was ok compared to dipole and directed mostly towards the counterpoise wire. Of course you need to retune the antenna every time you change the band. Anyway there is also wire in this antenna, though the wire is laying on the ground.

73, Jaakko OH7BF/F5VGL


#7

In reply to all:

Thanks everbody for suggestions, I will take time next week and test and experiment with the ideas i got from here.

73 / Chris
http://www.sm5kri.se


#8

In reply to F5VGL:

hello Jaakko

Of course you need to retune the antenna every time you change the band.

before purchase budistick i was sceptical with that too, but actually you changing bands in 5 seconds. You just move a wire to a preassempled socket on the coil and change your counterpoise length to a predefined (by a small mark you made at home) length. On any case KX1’s internal ATU manage the SWR around 1.5:1 to 2.2:1 (actually depends of the heigth you install counterpoise wire above earth).

Anyway there is also wire in this antenna, though the wire is laying on the ground.

sure :slight_smile:

best QSO till now: Sri Lanka from 728m ASL (SV/AT-011) on 20m with 3.3 Watts on early evening.

Yesterday i had a QSO with Ari, OH9VL on 14.059,5 , he was on 1W :slight_smile: (on 1409m, SV/AT-003, UTC 15:45), i didnt copy his antenna actually.

Since i got the KX1 and budistick i can consertate on climbing the summit while being absolute sure for the QSO’s. But to the other side i have not to fullfill the demands you have for chasers there for other bands or 2m QSOs. I dont carry a 2m radio any more (i use occasionaly one of fellow activators). I know that i will have the QSOs i need on CW in less than half an hour.

I agree that ham radio is to experimenting and I too will never stop for sure :slight_smile: But if the question is which portable antenna combine less weigth, less than 5 minutes of setup and more than 4 QSOs on less than half an hour (with power less than 5W) on CW, my experience says that budistick is the tool :slight_smile:

best regards
Panos, SV1COX


#9

In reply to G0AZS:
Hello. I made a normal Norcal Doublet except left the vertical portion over length. It reached the FC-901 ATU in my workshop that way through the open window. (Don’t panic folks - it’s a home experiment and I wanted to try a multiband antenna for HF above 14MHz as part of my ‘apprenticeship’. There’s only so much wire I can get in the air off the top of my 9m pole in our narrow garden. Linked dipoles for the hill and for 80/40/20 at home]

Is the following approach correct? Cut the vertical section to the correct length and join to some RG58 coax in a chocolate block connector. Make 6 coils of coax as a choke and then I’ll be able to extend the feeder towards the operating position. Or leave the ribbon feeder as it is?

Incidentally where is a good source of brass bodied, silver plated connectors with the PTFE insulators “UHF”, N and BNC]? The ones that can be soldered in the fashion beloved of radio licence instructors rather than the shiny plugs and sockets in Radioworld and Maplins.
best wishes
David 2E0DAI


#10

In reply to M6WOW:

Look for connectors made by companies like Greenpar, Radiall, Coline, Amphenol, or Andrew and you wont go too far wrong.

You can get them new from places like RS and Farnell. There’s a lot of dross on the market as you say but you can find real bargains at rallies. Grub about in the boxes of slummy you find on the floor and you can nearly always find a real gem or two for coppers. If you need them in a hurry then not everything sold by the grot shops like Maplin is bad. Some of the stuff is but they do sell some decent stuff.

Andy
MA0FMF


#11

In reply to M6WOW:
Hi David

The “vertical section” in the Norcal doublet is not a radiator, it is just part of the twin feeder to the doublet.

All you need to do is bring the feeder right back to the balanced twin feeder terminals on your ATU (I assume it has them but I don’t know your ATU model).

Note that the only influence the length of this feeder will have is in the impedance presented to the tuner. Sometimes, if it is difficult to match on some bands, trimming the length of the twin feeder will help.

Good luck…

73 Marc G0AZS


#12

In reply to M6WOW:
David
Try this guy for decent plugs and connectors :-

http://www.whwestlake.co.uk/

He attends most of the rallies, and can send stuff in the post too. I have used him for years, “work” also buy connectors and cable from him.

73

Tim
G4YTD


#13

In reply to G4YTD:

An excellent company to deal with Tim. They happen to sell the PL259 plugs that use a pressure sleeve fitting similar to BNC and N plugs. So fitting is easier and you don’t end up searching for a blacksmith’s forge to heat the plug body so you can solder the screen and make joint stick!

e.g. normal PL259 is 70p. Silver plated PL259 with PTFE insulation and pressure sleeve fitting £3.00

You get what you pay for but for many applications the cheap PL259, if fitted well, will be more than good enough. The only problem being fitting it well. Not a problem on the pressure sleeve type and you also get a more weatherproof seal than usual.

Also, Westlake sells an SMA plug for RG58 cable. Ideal if you want to make a lead to fit a modern handheld rather than using one of those adapters that strain the bejeezus out of the handy connector.

Andy
MA0FMF


#14

In reply to MM0FMF:
Hi Andy
Envelope arrived a couple of minutes ago thanks :wink:

BTW Westlake also sell an SMA and a BNC made to fit RG174!!
You do need very good eyesight to work with them and a steady hand though…

73

Tim