Pages: 1 [2]   Go Down

Author Topic: Do the extra 30 watts from the FT1-2980 Make a Big Difference?  (Read 519 times)

N4UFO

  • Member
  • Posts: 1171
Re: Do the extra 30 watts from the FT1-2980 Make a Big Difference?
« Reply #15 on: December 21, 2021, 08:15:45 AM »

Quote from: N4UFO

...(takes 6 db increase to raise a typical S meter one S unit.)...




That's an oft-quoted standard for HF radios, but not at all the case
for most FM transceivers.  Regardless of the markings, most FM
rigs I've measured have a full scale display range of about 12 dB,
regardless of the markings on the scale.  And often that is done
with a bar graph driver, so you might have 7 discrete steps of
resolution.

I've seen the S-meter change from "S-9" to "S-9 +40 dB" with just
a 1 dB change in the output of the signal generator, because that
was the next display step.  Maybe that is one cause of some of the
inflated claims for antenna gain...

I stand corrected and had no idea... thanks for educating me. (40 plus years into the hobby and I am still just a learner)  :D
Logged

WB6BYU

  • Member
  • Posts: 20896
    • Practical Antennas
Re: Do the extra 30 watts from the FT1-2980 Make a Big Difference?
« Reply #16 on: December 21, 2021, 04:28:42 PM »

It’s not a spec that I’ve seen listed anywhere -
I only know it because I’ve measured the meter
response of my radios for transmitter hunting.
My attenuators have to have 10 dB steps - or less -
to avoid a gap where it is full scale on one setting
and no indication on the next.

WB6BYU

  • Member
  • Posts: 20896
    • Practical Antennas
Re: Do the extra 30 watts from the FT1-2980 Make a Big Difference?
« Reply #17 on: December 21, 2021, 06:27:32 PM »

Quote from: KE2SJ

...If I found an inexpensive 2m yagi, I'd put it up...




Fortunately, 2m beams are cheap to make, even if it is just a throwaway
antenna to test how big of a more permanent beam you need.

A simple 2-element quad will give you more gain than the higher power.

Or you can try 3 elements, this 4-element design, or this one.
Want more, here's 5 elements, and another.
That should give you an assortment of construction methods.

If you prefer yagis, there are many options as well.

Here are some simple ones.
I like the WA5VJB "Cheap Yagi" method of half-folded driven elements.

This one is really easy.

M0UKD designed a portable yagi.

DK7ZB has many different designs for different needs.

Or this one.

You can make it dual band.

And you can make it as long as you want.


Or, if you want to be a bit different, try a quagi.


There are lots of other options, but this should give you some
starting points.  I often build my yagis just by sticking stiff
wire through a piece of wood or PVC pipe.  In your case, that
will allow you to see how much difference it makes.

AF5CC

  • Posts: 1664
    • HomeURL
Re: Do the extra 30 watts from the FT1-2980 Make a Big Difference?
« Reply #19 on: December 21, 2021, 11:11:22 PM »

Replacing the LMR-240 with LMR-400 or Belden 9913 will improve your signal more than 30 extra watts will, and it will improve your receive capabilities as well.

73 John AF5CC
Logged

K1FBI

  • Member
  • Posts: 1475
Re: Do the extra 30 watts from the FT1-2980 Make a Big Difference?
« Reply #20 on: December 22, 2021, 03:53:46 AM »

Replacing the LMR-240 with LMR-400 or Belden 9913 will improve your signal more than 30 extra watts will, and it will improve your receive capabilities as well.

73 John AF5CC
Not exactly, with his 70 foot run he would still be 10 watts ahead at the end of the cable with the LMR 240 and the Extra 30 watts going in.

However he would gain on receive with the LMR 400 as you stated.
Logged

K7MEM

  • Member
  • Posts: 1058
    • JavaScript Electronic Notebook
Re: Do the extra 30 watts from the FT1-2980 Make a Big Difference?
« Reply #21 on: December 22, 2021, 06:33:55 AM »

If it's just one repeater you don't need a rotator

Quite true. However, I thought we were talking about "significantly more repeaters". I guess we never defined "significantly".

From my location, if I look out 10 miles there are 5 repeaters. At 20 miles, 10 repeaters. At 30 miles, 18. At 50 miles, 39. So as I look further out there are more repeaters and they are not all in the same direction. A rotator might help to single out just one.

There was a interesting demonstration of "line of sight" communication, when I was working in Germany. We dealt with ground mapping radar systems that were onboard F4s. The plane had film on board, but they didn't want to wait for the plane to land and the film to be processed. So they used a data link. The air base was on the highest hill in the area and the antenna (25' dish) was on top of the PIF (Photographic Interpretation Facility) building. The planes were flying at about 35,000'. Usually, we would lose their signal when they were about 90 miles away, but sometimes we were able to track them to 110 miles out. So even though there were no obstructions, the atmosphere often limited our range.
Logged
Martin - K7MEM
http://www.k7mem.com

W1VT

  • Member
  • Posts: 6071
Re: Do the extra 30 watts from the FT1-2980 Make a Big Difference?
« Reply #22 on: December 22, 2021, 07:29:32 AM »

https://www.ve2dbe.com/english1.html

Free software that can be used to predict VHF coverage area.
As well as the equally important terrain data!
« Last Edit: December 22, 2021, 07:31:47 AM by W1VT »
Logged
Pages: 1 [2]   Go Up