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I know that it's not actually an antenna either, but the circumstances require it to make a baton. Does anyone of you have any documents for this? The antenna should work with a power of up to 5w and at freq.. 118-136Mhz thanks
Buy that stick, you probably won't be able to make it. Interesting read on the subject:
http://www.aeroweb.cz/clanek.asp?ID=1231&kategorie=7
to make an antenna, is a better telescope, even if he is vulnerable, has better reception properties, as already stated in the article see above.
http://3.bp.blogspot.com/-zI7FZOTV2N8/UBV1_wrBnrI/AAAAAAAAMVE/wUPtObE8YAo/s1600/DSC_0500.JPGIf you want ultra flexible, indestructible 1/4 maybe ziaric, so use it as a supporting flexible element, bowden core from the tachometer, it is a crisis coiled steel rope, where a very high bending resistance is guaranteed.
He can be found on the srotak, also for free, you need at least a 55-60 cm piece.
If it is clogged with oil, dried petroleum jelly, etc. so just put it in a bottle from some mineral, etc, staci 1/2 liter bottle and gasoline is poured on it, or acetone and let it heat for a while, or you have to put it in the trunk of the car and it washes itself by driving.
Next, the spin is poured out, bottle cross section, the rope is taken out.
on steel rope, is well stretched “ponozku” from the braid of the coaxial cable, to increase the conductivity of that element.
On such a beam, a shrink sleeve is put on, just average, so that it can be drawn evenly over the stove, or a thermometer.
At one end, it is good to make a tube from a piece of a broken telescopic antenna and solder the end of it with a light bulb, it will be better in BNC, or some connector for the radio station, connect the living one how much.
A suitable diameter is adjusted in the connector by adding 1-2 layers of those bubbles, it is good to use a connector, not a crimp one, but screwdrivers.
For sure, it can be secured with a drop of second glue.
At the end of the antenna, so that no one gets hurt, it is good to stick and stretch with a shrinking ball, or a plastic coral, you can also use a protective sleeve against moisture from the optical connector, etc.Second option, is to use a tape measure, which fell apart, damaged destroyed, atp. To create a bond, similar to the antenna from RF12 (AT10)
Both systems, like a tape measure, so a steel bowden cable, can be combined, there are no limits to imagination..
https://www.google.sk/search?q=RF12+radio&biw=1440&bih=752&source=lnms&tbm=isch&sa=X&ei=CFw-VaiyFISVsAGRmYGQCg&ved=0CAYQ_AUoAQ#tbm=isch&q=AT+10+military+antena73!
The procedure for making a baton, for example:
modre A-Radio 3 / 2002 + program na http://www.aradio.cz/prog_do07.html , search for HELICAL3.EXE
Practically for sticks, it is very important to have a counterweight attached to the arm, I did experiments a month ago during a walk with my cat in the woods around the house and the difference was 20 cm original stick with and without a counterweight on 145 FM on ID51 pain in protocytes 2 az 3S , i.e. over 10dB! (when taking into account the accuracy of the S-meter measurement). The counterweight decided on “it doesn't work at all” a “it goes for 5” in boundary situations simulated in one place by switching execution. Protistanica over the hill approx. 8km. Counterweight 50 cm 0,75 v silikone naletovana na ocku fi6, father under the SMA connector of the antenna.
The counterweight can also help with the antenna, where it is assumed that it is not needed, 1/2 The L telescope has improved by about half to a full S.
Since the experiments, I use a handle with a rubber winch only with a counterweight, and suddenly 0.5W instead of 5W is enough for the same readability 😉 .
When you put your hand on the table, the weight of the counterweight increases even more…Hi Tona. I understood it well – equal 50 cm e.g. copper wire with a diameter of 0,75 mm to fly on the eyelet and put in the tube? Wouldn't it be better to use exactly 1/4 lambdy, t.j. 51,5 cm?
You have to put a shortening factor there, so for erko 300/145.15MHz=2.066m/4=0.516m*0.95=0.49m.
It goes well with the counterweight, but worth a try to do
you're Slim Jim's, see
http://www.m0ukd.com/calculators/slim-jim-and-j-pole-calculator .Or do it from the TV dual line according to http://ok1ike.c-a-v.com/soubory/2m_slim_jim.htm. There may not be a tube for a portable.
I'm pise Dusan, should be started with a shortening of the bladder, I used 0,75 cable with silicone insulation and a heat-shrinkable eyelet. If it is to be absolutely exact, then the length of the plug from the connector must also be included in the calculation 😉 But will you have 49 or 51 you don't know cm, it will do a maximum of tenths of a dB 😉 Not to mention detuning the body, by hand, surroundings, with a homogenite pole… On FM, you have a chance to distinguish a difference of 2-3dB in the signal under borderline conditions.
Dusan, the snail is awesome, but the advantage of the rubber band is its mobility, krapty can easily wake up when the cat is standing for a long time 😉 . For a portable with a more permanent position than a few minutes (UNDER) I have in stock a collapsible 3-ele yagi and/or a 1m telescope that looks like “polka”, but for the first time, the snail is a really great antenna, which goes from a double line to 1x if the dimensions are respected, and for a couple of beers if a person has to buy it all.
After time, everyone will have their favorite and guaranteed best antenna. At one time I preferred HB9RU see
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=14404
It is about what the antenna will be used for. You can say that, that HB9RU is “half” yaginy. It is directional, it has profit and acceptable dimensions.
Antennas such as baton and similar have different parameters than e.g. classic OK1KRC. It always depends on the circumstances under which the antennas will be used, but that was already written here.
You need to focus on the broadcast location, because sometimes it is enough to move o 2 to 3 meters and the signal is much better. The height of the antenna above the ground is important. For example, the erko from the Zvolen hill can be heard, but it is not possible to invoke s 1 W. You have to go down to the cable car building and it goes like wine on a rubber band from the bench. A handrail can be used instead of a counterweight.Excellent, United Kingdom and Vatican.
