Forum Replies Created
-
Posts
-
For those who would like to program their HT’s for the fox hunt, the fox will be howling on 146.565 MHz. When you get close to his den, you might want to try the third harmonic (to attenuate the signal) of 439.695 MHz.
When you find the fox, there’ll be a notebook in a plastic bag along with a pen. Record your name, call, the date and time.
Have fun and good luck.
Hi Jamey,
This is a great story – thank you for posting it. How do you like the Elk yagi antenna?
Would you consider posting this same article on our Blog so that folks outside the club could see it (and we can include it in our next newsletter)? If you want to do this and want some help, give me a call.
Thanks and 73,
If you have a half hour or so and would like to learn more about fox hunting here’s a link to a very good video.
[quote quote=3160]Sounds like fun Wayne. Can you tell us a little more about the sort of antenna we need for this? I have an arrow antenna that I could connect to an HT. Would that work? What else would I need to bring? 73, [/quote]
Sure thing. Arrow makes some nice antennas. They make a loop antenna that is especially good for direction finding. [attachment file=3166]They also make a great 3 element 2 meter hand held antenna that would probably work fine. [attachment file=3167]
It looks a lot like the tape measure yagi I made and use. The Arrow antennas made for satellite communications probably have more gain than you’d want for fox hunting.
Along with the tape measure yagi I built (search google for plans) I built an eight inch loop (receive only) that attaches to my HT. In this case, I think less gain is better. One other thing I take along is a short piece of very thin coax. When I get close to the fox I put this on in place of an antenna and use my body to attenuate the signal and determine the direction. A straightened paper clip might work just as well.
There’s really nothing else to bring along for hunting. Maybe some bug spray and watch out for poison ivy. Hi hi. A map of the area might be of some help. You can draw intersecting lines to help locate the fox.
Fox hunting is a bit of an art and takes a while to perfect. It’s great fun for young and old, newly licensed and old timers. Since it’s receive only you don’t even need a license. A 2 meter receiver and various attenuated directional antennas and you’re good to go.
Sounds like fun Wayne. Can you tell us a little more about the sort of antenna we need for this? I have an arrow antenna that I could connect to an HT. Would that work? What else would I need to bring?
73,
Hamilton’s advise is sound here. LMR-400 is a good choice for any HF application requiring power handling. When selecting coax, the following considerations should apply:
1) What is the maximum frequency that the coax will be used at? Loss related factors will increase with frequency.
2)What is the total length and how much loss does a given coax have at the desired length? I generally engineer my feedline systems to have no more than 1 dB of loss from the feedpoint of the antenna to the back of the transceiver.
3) What is the likely maximum SWR that the system will be operated at? If you will be operating at SWRs of 2:1 or higher, the additional losses due to the higher SWR as we as the associated higher power levels generated on the coax need to be considered. There are several loss calculators online that will do these calculations for you. You can find one here.
4) Given the intended power levels and the associated increases in power due to SWR above 2:1, choose a coax that can handle the desired power. Its best to consult the manufacturer’s specification sheet for the coax that you have in mind to determine the power handling capability of the coax you are considering. Note that power handling capability will also depend upon the maximum frequency that the coax will be operated at.
5) There are some considerations depending upon how you will mount your coax. For example, if you intend to direct bury you coax, you will need a coax cable that is designed of direct burial.
LMR-400 coax is generally a good choice for most high-power HF and 6m (up to 50 MHz) applications for lengths up to 150 ft or so. You can see the specifications for LMR-400 here.
73,
Hi Hamilton,
Thank you! We might want to use you IC-7300 as one of the main stations for Field Day. Do you have one or two IC-7300 transceivers?
73,