DXer needs help imroving fm recption
 

I have a Fisher FM 2110 tuner Radio Shack antenna 20ft to 25ft high. What
can I do to improver the recption that does not cost $$ I live in Houston Tx
and want to get stations atleast 100 to 150 miles away.

I have a Fisher FM 2110 tuner Radio Shack antenna 20ft to 25ft high. What
can I do to improver the recption that does not cost $$

Nothing that does not cost money, unless you have amplifiers and/or push-up
poles in your junk box. Antenna mounted amplifiers will help, but you have to
run power up to them, or use a photovoltaic array. Amps at receiver will not
generally help. Probably the cheapest solution is to get the antenna at least
another 10' up, more if possible.
73 Gary N4AST

I have a Fisher FM 2110 tuner Radio Shack antenna 20ft to 25ft high. What
can I do to improver the recption that does not cost $$

Nothing that does not cost money, unless you have amplifiers and/or push-up
poles in your junk box. Antenna mounted amplifiers will help, but you have to
run power up to them, or use a photovoltaic array. Amps at receiver will not
generally help. Probably the cheapest solution is to get the antenna at least
another 10' up, more if possible.
73 Gary N4AST

DJboutit wrote:
I have a Fisher FM 2110 tuner Radio Shack antenna 20ft to 25ft high. What
can I do to improver the recption that does not cost $$ I live in Houston Tx
and want to get stations atleast 100 to 150 miles away.


At 20 feet high your antenna can effectively see the horizon at about 6
miles from your house. So, to receive a FM station 150 miles away the FM
station needs to have it's antenna at an elevation of somewhere around 2
miles high. That is simply not feasible!!

At 100 miles the radio station needs an antenna about 1 mile high. Still
not feasible!

Basically, you should be able to receive a FM signal from a very well
equipped FM station out to 50 to 60 miles from their transmitting
antenna. Even at 60 miles the broadcast antenna needs to be around 2000
feet high.

DJboutit wrote:
I have a Fisher FM 2110 tuner Radio Shack antenna 20ft to 25ft high. What
can I do to improver the recption that does not cost $$ I live in Houston Tx
and want to get stations atleast 100 to 150 miles away.


At 20 feet high your antenna can effectively see the horizon at about 6
miles from your house. So, to receive a FM station 150 miles away the FM
station needs to have it's antenna at an elevation of somewhere around 2
miles high. That is simply not feasible!!

At 100 miles the radio station needs an antenna about 1 mile high. Still
not feasible!

Basically, you should be able to receive a FM signal from a very well
equipped FM station out to 50 to 60 miles from their transmitting
antenna. Even at 60 miles the broadcast antenna needs to be around 2000
feet high.

Err isnt FM broadcast between 88-108MHz? There is some "bend" to those
frequencies.

The simple answer to the problem is;
- more antenna height
- low cable loss (preamp?)
- low noise figure (good preamp)
- directive/gain antenna

Each of these requires $$ and it is a case of how *much* better it needs
to be. I'd initially suggest a low noise preamp as having best bang for
the buck. You can certainly buy them but it may be worthwhile looking a
a low noise design from a handful of components (say $5-10) I built one
up once from (I think) an MRF901. Worked well for TV and FM radio.

And maybe go to 30ft on the mast. Local obstructions might be a problem
too. ie make sure that your 20ft pole isnt right next to a 18ft house....

Antenna gain is a tricky one because most designs arent quite wide
enough to cover the entire band with good gain. LPDA's and helixes might
do the job though. Depends though on what you want to spend or make.

I should also point out that if you have any strong local FM stations
preamps may get overloaded and not perform well at all.This is the price
you pay for putting a wideband amp at the RX front end.

Hope this helps

Cheers BOb VK2YQA



bcnuup does it better




David.Shrader wrote:
DJboutit wrote:

I have a Fisher FM 2110 tuner Radio Shack antenna 20ft to 25ft high.
What
can I do to improver the recption that does not cost $$ I live in
Houston Tx
and want to get stations atleast 100 to 150 miles away.


At 20 feet high your antenna can effectively see the horizon at about 6
miles from your house. So, to receive a FM station 150 miles away the FM
station needs to have it's antenna at an elevation of somewhere around 2
miles high. That is simply not feasible!!

At 100 miles the radio station needs an antenna about 1 mile high. Still
not feasible!

Basically, you should be able to receive a FM signal from a very well
equipped FM station out to 50 to 60 miles from their transmitting
antenna. Even at 60 miles the broadcast antenna needs to be around 2000
feet high.

Err isnt FM broadcast between 88-108MHz? There is some "bend" to those
frequencies.

The simple answer to the problem is;
- more antenna height
- low cable loss (preamp?)
- low noise figure (good preamp)
- directive/gain antenna

Each of these requires $$ and it is a case of how *much* better it needs
to be. I'd initially suggest a low noise preamp as having best bang for
the buck. You can certainly buy them but it may be worthwhile looking a
a low noise design from a handful of components (say $5-10) I built one
up once from (I think) an MRF901. Worked well for TV and FM radio.

And maybe go to 30ft on the mast. Local obstructions might be a problem
too. ie make sure that your 20ft pole isnt right next to a 18ft house....

Antenna gain is a tricky one because most designs arent quite wide
enough to cover the entire band with good gain. LPDA's and helixes might
do the job though. Depends though on what you want to spend or make.

I should also point out that if you have any strong local FM stations
preamps may get overloaded and not perform well at all.This is the price
you pay for putting a wideband amp at the RX front end.

Hope this helps

Cheers BOb VK2YQA



bcnuup does it better




David.Shrader wrote:
DJboutit wrote:

I have a Fisher FM 2110 tuner Radio Shack antenna 20ft to 25ft high.
What
can I do to improver the recption that does not cost $$ I live in
Houston Tx
and want to get stations atleast 100 to 150 miles away.


At 20 feet high your antenna can effectively see the horizon at about 6
miles from your house. So, to receive a FM station 150 miles away the FM
station needs to have it's antenna at an elevation of somewhere around 2
miles high. That is simply not feasible!!

At 100 miles the radio station needs an antenna about 1 mile high. Still
not feasible!

Basically, you should be able to receive a FM signal from a very well
equipped FM station out to 50 to 60 miles from their transmitting
antenna. Even at 60 miles the broadcast antenna needs to be around 2000
feet high.

"DJboutit" wrote
want to get stations at least 100 to 150 miles away.
_________________

VHF basically is a line-of-sight service, although favorable propagation
conditions can extend that range at some times of the day and seasons of the
year, for some receiving locations. When those conditions exist, it doesn't
take much of a receiving antenna. When they don't, no practical receiving
antenna will work well.

For an FM station radiating 100kW from a 1,500 foot height above average
terrain, at a 93 mile range the FCC's f 50,50 curves predict a field
strength of about 75 microvolts/meter at a receiving antenna height of about
30 feet above ground. And that only occurs for "uncluttered" paths to 50%
of locations at that distance, 50% of the time. Urban clutter and/or lower
rx antenna height will reduce those fields strengths considerably.

As a cal point, my situation with St. Louis FM stations parallels the
conditions above. Using a McIntosh MR-73 tuner with a Wineguard CH6065
10-element FM antenna (10dB gain), they are received with reasonable stereo
quality about 1/2 the time.

RF

Visit http://rfry.org for FM broadcast RF system papers.

"DJboutit" wrote
want to get stations at least 100 to 150 miles away.
_________________

VHF basically is a line-of-sight service, although favorable propagation
conditions can extend that range at some times of the day and seasons of the
year, for some receiving locations. When those conditions exist, it doesn't
take much of a receiving antenna. When they don't, no practical receiving
antenna will work well.

For an FM station radiating 100kW from a 1,500 foot height above average
terrain, at a 93 mile range the FCC's f 50,50 curves predict a field
strength of about 75 microvolts/meter at a receiving antenna height of about
30 feet above ground. And that only occurs for "uncluttered" paths to 50%
of locations at that distance, 50% of the time. Urban clutter and/or lower
rx antenna height will reduce those fields strengths considerably.

As a cal point, my situation with St. Louis FM stations parallels the
conditions above. Using a McIntosh MR-73 tuner with a Wineguard CH6065
10-element FM antenna (10dB gain), they are received with reasonable stereo
quality about 1/2 the time.

RF

Visit http://rfry.org for FM broadcast RF system papers.