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6

According to this online coax loss calculator, the loss of 50 feet of new Belden 9258 RG-8X with an antenna with an SWR of 1.5 is 4.29 dB at 450 MHz (UHF), so the loss for 100 feet of the same coax would be 8.6 dB. If you switched to fancier coax such as LMR-400, the loss for 100 feet of coax would be 2.8 dB. So if you bought another 50' of RG-8X your coax ...


3

My personal experience: Baofeng UV-5R, works fine with stock rubber ducky antenna. Made a simple quarter-wave dipole antenna, connected to my radio with about 10 feet of cable. It transmitted much better than stock antenna. However, there was a problem with reception. The radio would receive the first transmission, and but would not re-open the squelch until ...


3

My experienses on 2 meters when I was living in southern Finland (near Helsinki). My Finnisf call sign was (and still is) OH2AXE. I did not have 70 cm equipment. Antenna: 2 x 2 stack of double hybrid quads, gain about +12 dBd, about 10 m above ground. 50 W homemade linear amplifier. Most of the time the TX power is not so critical, even 5 or 10 W is enough ...


3

Yagi antennas require an exact set of lengths and spacings to work properly. The lengths are all near a half wave but there is some subtle tuning to get the currents to the appropriate phase. Spacing can be between a quarter and a half wave but different spacings affect the optimum lengths. So your example of a 5/8 wave reflector won't work as a reflector, ...


2

In my experience the parts allocated to PMR are extremely busy, it's the most popular band for walkie talkies and car radios, best compromise between antenna length (60 MHz is quite bulky) and path loss + diffraction (450 MHz is not as nice). But busy doesn't mean 0.5 Erlang, because analog FM and Push To Talk are so inefficient. Without actually analysing ...


2

https://www.amsat.org/status/ will show you a list of birds and if there has been any activity reported during the last week. Reports are crowd-sourced, the page allows you to drill down into each report and see who reported and when. Even reports of "not heard" are shown.


1

I applaud your attempt to satisfy a need. Unfortunately, your design will not achieve your goals. Here is a model of your design: The pattern shows none of the front-to-back directivity you want from a "beam" antenna. In fact, the pattern is not affected at all by the addition of the "reflector" or the "director". The pattern ...


1

Canadian frequency spectrum allocations can be found here: http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10759.html#t2 Hope this helps.


1

Check out this video from AG6IF who built a 2m slot antenna out of an old parabolic dish. His application was for home mounting a stealthy antenna, but the interesting notion there is that the slot is curved. His video shows a chart from an analyzer as well. This indicates to me that it's worth trying your idea too. Hope this is helpful!


1

On a vehicle with a steel body and roof, the most feasible 2 meter slot antenna design is a pair of square flat plates with spacers to maintain the space between them. The slot ends up being the horizontal space between the plates. The top plate is connected to the center of the coax feed line, and the ground is the bottom plate to which is joined the ...


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