Kite Antenna Part Deux

Old Reflector
1

There is little doubting, Amateur Radio is the most frustrating hobby in the world. It seems as if Sods Law was invented for Radio Hams.

Take today, I planned a kite antenna activation from G/SP-013 Gun, in the knowledge that we`ve had nothing but wind for a week and the BBC weather forecast predicted 10mph winds for Leek, about 3 miles from the summit.

Rather foolishly, I believed the BBC WX forecast!

On arriving at the summit, I set about launching the kite in a wind that certainly was not 10 mph. After about half a dozen attempts, the kite finally caught a gust and took off. Rather gingerly, it started to climb and as I reeled out the antenna wire the additional weight slowed its rate of ascent. I figured that there was about 65 metres of the 100 metre roll of antenna wire in the air when I tied it off. The kite seemed stable and hung in the air quite nicely. Oh for another few MPH of wind.

Tuning up the antenna for the 40m band produced huge signals. Sounded more like I was on 2m FM. Wherever I tried to slot in on the frequency, I was battered by QRM :frowning:

Eventually, I managed to slot in and self spot. It seemed every signal was 5/9. In 18 minutes there were 29 calls in the log.

A quick QSY to 20m to work the S2S with OE/DB2TK produced a call from CT1BQH asking me to QSY up 5 KCs to work him. A further 25 stations followed him up there.

It went quiet for a few seconds giving me a chance to QSY to top-band and a chance to run out more antenna wire. However top-band on Gun is not the same as top-band on Shining Tor, leaving me with with just 2 contacts in the log, G3RMD and G4ODU. I did hear John GW4ZPL, just too weak to work with S8 of noise on my meter. So back to 20m where I worked just 3 calls before the kite dropped dramatically! I heard Bill W4ZV call me and as I’ve gone to return his call the kite antenna fell out of the sky. With no chance of a re-launch it, it was back to the fishing pole antenna. To add insult to injury, it started to snow :frowning:

The drop in signal strength on the fishing pole after the kite was surprising! Nevertheless, I rattled off another 33 calls on 20m including Rich N4EX and Bill W4ZV. Very disappointing the kite decided to give up the ghost just as Stateside started to call in, but I guess that`s nature for you :frowning:

4 Summit to Summits and 95 contacts made for a nice day.

Working with a kite antenna is enormous fun if not enormously frustrating. There`s plenty of work to be done with this fascinating antenna and I look forward to continuing my experiments.

Just a quick note. I`ve received a number of emails about this antenna and will get round to sending answers ASAP. I won’t give out callsigns.

Paul in the States, I’ll send off the info you have asked for and will include some photos which should be helpful. To the UK stations, I`ll reply very shortly. It seems we may see more kite antennas on SOTA summits before too long.

73 Mike
2E0YYY

2

In reply to 2E0YYY:

Hi, Mike, I could hear you on Top Band and called you several times whilst you were CQing about 11:35, you did call QRZ? at one point after my call. I wonder if your receiver was blocking, perhaps you might try the attenuator next time before giving up? You were weak but fully readable with me.

73

Brian G8ADD

3

In reply to 2E0YYY:
Hi Mike,
Thanks for doing Top Band again. Pleased to have a successful qso. Sorry to hear that your kite did not fully cooperate and thanks for persevering.
73,
Frank

4

Great report Mickey, really enjoyed reading that one.

Is there a documented minimum and maximum wind speed for your kite antenna to work properly? ie, what’s the minimum amount of wind to keep it flying, and what is the maximum before there is a danger of damage or safety issues?

Tom M1EYP

5

In reply to G8ADD:

Hi Brian,

I know there were stations there but was unable to pull them out of the S8 noise and did say QRZ a couple of times. The antenna was a lot lower than I would have liked. TBH, I could have chosen a better day for playing kite antenna, it seems the elements were against me :frowning:

73 Mike
2E0YYY

6

In reply to M1EYP:

I’ve asked Mike several times about the antenna, the earthing and kite but he keeps playing all coy and ignoring the questions. Must be a big secret for some reason!

:wink:

Andy
MM0FMF

7

In reply to M1EYP:

Great report Mickey, really enjoyed reading that one.

Is there a document minimum and maximum wind speed for your kite
antenna to work properly? ie, what’s the minimum amount of wind to
keep it flying, and what is the maximum before there is a danger of
damage or safety issues?

Hi Tom,

The problem with a kite antenna is the more wire you wish to run out the more wind that is required to support it, unless you wish to fly a bigger kite which brings with it more problems.

The wire I was using, IIRC, is about 18 gauge so with about 250 feet dangling from the kite, pretty heavy. This time, I dispensed with the kite line and this made things much easier to control .

I`ve just dug out some electric fence wire which weighs virtually nothing and will give it a try from a summit on Saturday. This shoud be interesting :wink:

73 Mike
2E0YYY

8

In reply to MM0FMF:

In reply to M1EYP:

I’ve asked Mike several times about the antenna, the earthing and kite
but he keeps playing all coy and ignoring the questions. Must be a big
secret for some reason!

Do keep up at the back, Andy :wink:

Both the earthing and kite detais have been posted here within the last few days.

The Kite is an HQ 1.7m Power Sled and the earthing is a 1 Mega Ohm 20 Watt arrestor built by Ray G7TAS of Prowhip Antennas.

Edit…

Apologies

You may be right about the kite details, I seem to have answered that question in reply to one of the emails I received

73 Mike
2E0YY

9

In reply to 2E0YYY:
I’d have thought that with all the hot air on Gun yesterday - your kite would have stayed airbourne for weeks!

LOL

Or are you just having difficulties keeping it up?

10

In reply to M1EYP:
From http://www.skyhighkites.co.uk/shop/product/1651/

Width 165 cm / 65"
Height 104 cm / 41"
Sail Nylon
Frame Fibreglass 2 mm
Line incl., Polyester 45 kp / 100 lb.,60 m / 200 ft. on spool
Wind 2-5 Bft. (10-38 km/h, 6-24 mph)
Age + 14

HTH
Roger G4OWG

11

Thanks Roger!

12

In reply to G4OWG:

I just found this. Interesting I thought.

http://www.mydarc.de/dl6ip/kite%20antennae.html

Mike G6TUH

13

In reply to 2E0YYY:

Nice to work you on the kite Mike! I just wanted to let you know your signal was well down from normal. It could have just been conditions but here’s another thought. 250’ is approximately 3.5 wavelengths on 20m. The radiation pattern is mainly a big lobe off the end of the wire. If the wire was near vertical it would have little low angle component. If more horizontal (i.e. about to crash) it would radiate mostly in the direction of the tip.

I imagine it would work well on 80/160, but probably not so well on the higher bands. Anyway thanks for your efforts and we appreciate any means to send a little RF our way!

73, Bill W4ZV

P.S. 20m is often open at 11z but many EU activators never leave 30/40m. :frowning:

14

In reply to W4ZV:

I imagine it would work well on 80/160, but probably not so well on
the higher bands.

To be honest, I’m still messing about with it.

Anyway thanks for your efforts and we appreciate
any means to send a little RF our way!

You`re welcome Bill, getting DX into the log, especially Stateside, is what makes SOTA such great fun.

Gun G/SP-013 is not the greatest summit in the world for take-off. Cloud G/SP-013 is much better and I recall you did comment on my signal from this summit.

P.S. 20m is often open at 11z but many EU activators never leave
30/40m. :frowning:

Indeed, I worked Barry N1EU on the 20m band at 0920z one morning from a North Wales summit and at 0858z from a Mid Wales summit.

73 Mike
2E0YYY

15

In reply to 2E0YYY:

Both the earthing and kite detais

I thought I read some but not all of the details. I understand about replying in emails and thinking you’ve replied elsewhere. My XYL didn’t understand why the first thing I did after checking the view of the Atlantic on arriving at our hotel last year in Madeira was to get my emails. Since leaving Scotland there were only about 50 to browse! Half the time I think I’ve answered stuff when I’ve been asked it twice and only answered it once.

So the resistor is the static discharge path and a very sensible thing to have. But that’s for discharging any accumulated static that hanging long bits of wire in the air will collect.

Where’s the RF earth? Or where does the earth current go?

Andy
MM0FMF

16

In reply to MM0FMF:

So the resistor is the static discharge path and a very sensible thing
to have. But that’s for discharging any accumulated static that
hanging long bits of wire in the air will collect.

Where’s the RF earth? Or where does the earth current go?

Hi Andy,

I’ll take some pics of the inside and outside of the arrestor and send then with all the others to Mark G0VOF who is going to post something.

73 Mike
2E0YYY

17

Well, the best laid plans etc, etc.

I’d alerted for G/SP-004 Shining Tor but on arriving, I opted to move to G/SP-015 Cloud. So with my schedule shot, I arrived at cloud, scooped up the rucksack and kite antenna and took the short walk to the trig point. From the off, I had my doubts about launching the kite, nevertheless, I gave it a try.

The kite took-off but to be honest, it never really looked that happy to be in the air, there was a definite lack of wind. Maybe I should have had a bigger portion of beans with my breakfast :frowning:

A quick shout on 40m brought just 21 contacts so a QSY to 20m was the order of the day.

A self spot and the cavalry arrived. Phil G4OBK blasted himself into the log from Pickering, marvellous contact Phil and thanks for the spot :wink:

Great to hear Barry N1EU coming back on his repaired antenna. Thanks for the call and spot Barry!

There’s little doubting, the kite is an excellent performer on the 20m band with about 65 contacts logged in very short order. The plan was to work some top band however, the kite antenna refused to tune-up, I suspect maybe water ingress somewhere, anyhow, the antenna was having none of it. I’d spoken to Mark G0VOF on 20m hoping we could make a contact, so I was bitterly disappointed that it wasn`t going to happen.

Tuning up on 15m presented no problem, however, this band is just not performing at the moment. It was a small consolation for Mark that he made the trip to The Cloud on 15m too. Just 9 contacts on a band that has produced some fantastic DX for me from this summit. Not today though :frowning:

It was a this point the kite decided it no longer wanted to defy gravity, so it was abandoned in favour of the fishing pole. A quick return to 20m to try and find some Stateside contacts, produced the ultra reliable Rich N4EX and Bill W4ZV, once again, thanks guys, also a summit to summit with LA5XTA . It was around this time Tom M1EYP joined me on the summit. Tom was hoping to see the kite in action but sadly the only thing for him to photo was the kite laying on the ground surrounded by about 250 ft of wire :frowning:

A quick shout on 2m brought in just over 20 contacts including S2S with Karen, Barry and Ricky up on rarely activated GW/NW-037 Y Garn. It was at this point, I handed over the station to Tom giving him a much better chance of contacts than on his HT.

Nice days radio with 119 contacts logged. A big thanks to Mark G0VOF for all of your help today.

73 Mike
2E0YYY

18

In reply to 2E0YYY:
Thanks for the s2s today. Had a hard time reading yor signals, your audio was realy poor, do you know what it was?
Annyway, hearing S2S, i had to work it, even that it sounded like you was talking into a bucket, hihi.

What kind of wire are you using on your antenna?
Guess it has to be light enough, but also strong enough.

Edit: found the answer, by reading the tread…

73 Erik
LA5XTA

19

In reply to LA5XTA:

Hi Erik & Mike,

Erik,

Mike had some RF getting into his microphone today when using 21 MHz SSB. I had worked him earlier on 14 MHz SSB & his audio sounded fine then. After discussing this with Mike on the air I think we determined that it was a lack of a good RF Earth / counterpoise on 15m that lead to the audio problems. However, congratulations on the S2S :slight_smile:

Mike,

Thanks again for the contacts today & well done for giving the kite antenna another try. Your pile-up on 20m SSB when I called you was very impressive.

Thanks & 73,

Mark G0VOF

20

In reply to G0VOF:

I think we determined that it was a lack of a good RF Earth / counterpoise on >15m that lead to the audio problems.

I’ve asked Mike 4 times on here and once by email what he was using for an RF earth and he has not answered other than showing what he used to bleed static from the antenna. It’s a fairly good bet that there is no RF earth per se and the only RF return current to earth is via the parasitic capacitance/inductance of the equipment. The whole setup will be RF hot and more so at some frequencies than others depending on the random length of the wire and its random position in relation to the TX and earth. The return path for 15m would seem to include the microphone cable today.

You can minimise the current to earth by making the antenna voltage fed not current fed which in simple terms means making it close to a multiple of 1/2waves at the frequency of choice. You’ll need a matching unit to transform the high impedance to 50Ohm but from there a simple counterpoise or even the parasitic C/L will be more than enough to handle the return current.

You can ignore the theory if you want but that doesn’t mean the theory will ignore you. The laws of physics can be downright persistent in their inflexibility. :slight_smile:

Andy
MM0FMF