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Hi,
Hi,
I’m going to my friend’s house to have him listen to my newest hobby, 91.5 FM. From my car radio I could hear the music blasting. As soon as I enter his house, turn on his portable FM radio (receiver) to 91.5 and all I hear is noise.
Go back to my car, turn on my car radio everything work great. Parked my car in his Garage, turn on the car radio to 91.5, the music blasting. OK! Take his portable FM radio to my car, all I hear is noise.
What am I doing wrong?
Thanks,
Jude
Total posts : 45366You have experienced first hand the difference between a great receiver and a poor receiver. No two radio’s are alike.
Especially when it comes to car stereo’s and portables.Your friends portable may be more suitable for listening to stations with way more power than your part 15 station is legally capable of producing.
And i am not saying his radio is junk, it’s just a matter of sensitivity.Car stereos use not only the car antenna to receive signals but the body of the car acts as part of the antenna system combined with the sensitivity standards set forth by the manufacturer.
You may want to try a few things, like maybe attaching a wire to your friends portable radio, say maybe add 2 feet of wire to the end of his antenna. Or place the radio close to if not on the window seal on the end of the house closest to yours, remember fm is line of sight and sometimes car stereos can ignore this rule while the portable you mention might rely on a big signal or true line of sight to receive a listenable signal. Another option is bring a radio with you from home and try receiving your station in your friends house.
If he has a old tv antenna on the roof , maybe you can attach the cables feeding that tv antenna into the portable radio using alligator clips.
One more thing before i post this, houses are made of much denser materials than most garages. This is a way to reduce the cost of building materials. So the house may have more materials between the walls that could block reception.
Total posts : 45366Portable FM radios, and even most modern FM stereos,are designed to hear very strong signals in the thousands of watts range, as opposed to the nanowatts legal Part 15 stations output. Plus their selectivity (the ability to reject strong signals adjacent to the one you’re trying to listen to) is usually very weak – thus, these strong signals nearby bleed into your Part 15 one, and obliterate it (literally).
I’ve had good success with older home stereos, such as the 1970s Marantz and Pioneer tuners – coupled with a reasonable dipole antenna, they approach (but don’t meet) car radio sensitivity and selectivity. You can connect a good outside antenna to them and even exceed car radio ranges. Plus they generally sound better.
Some other things to try – broadcast in mono, rather than stereo. Your signal won’t go any further, but will be far more intelligable throughout its range. The older tuners also allow you to select a Mono FM mode, which performs better.
Good luck.
Total posts : 45366There is not much to add regarding the OP’s situation except to suggest that you might consider repositioning your transmit antenna closer to your neighbor.
I agree with the comments about modern tuners not performing as well as the vintage units. With the signals available on cable and high powered broadcast stations the need for superb sensitivity is relaxed and costs can be lowered.
Since my early days, I have used car radios as receivers in my workshop. My first was a junk yard 25 cent remove it yourself tube AM radio from a Buick. I removed the vibrator and replaced the 0Z4 rectifier tube with diodes and powered it from a 6 VAC filament transformer. With a 3 foot whip antenna I received stations from all over the Midwest and the audio power output drove a 12 inch salvaged TV console speaker to the point where my parents considered making me homeless.
This involved approach would only appeal to a radio nut and probably the only thing to try is for your neighbor to rig an antenna to his receiver and tape it to a window.
Total posts : 45366Hi Jude!
In 2004 when I started my current Part 15 station,
it was on FM. I originally built the studio on the front
enclosed porch. It had a big window, and I just placed
the transmitting antenna in that window. It was line of sight to
the house where the listeners were. (That was a few hundred
feet away.)My son and his friends were doing most of the broadcasting,
and there were people in that house that were listening almost all
of the time.One of the listeners in the house said she just kept trying different
radios until she found one that received the signal well.My station transmitter was also running in mono at the time.
After my son and his friends eventually lost interest, I decided
to build a much better studio and try experimenting with AM
Part 15 transmission.Anyway, maybe your friend might have different radios to try.
Keep us posted if you can. Everyone here is always glad to
hear about another Part 15 operation coming on the air!And to Neil: I love your story about the car radio.
Long ago, I heard KSL/Salt Lake City, UT/1160 kHz on my Dad’s
car radio in Rhode Island when 1160 was pretty much
just KSL at night. My Dad’s car radio was still in the car, though.Best Wishes,
Bruce, MICRO1690/1700
Total posts : 45366Another advantage of using a car radio outside a car is the relative lack of noise. Even in a car that is heavily noise filtered, I notice a significant difference in my AM signal at the fringes of its range with the car engine off; weak but virtually no static (so easily listened to, at least with my Alpine tuner) vs very staticy and virtually unlistenable wtih the engine running.
Total posts : 45366I have my FM Transmitter set as high as possible without it being in the attic.
I’ve tested my range with everything from a portable to a Car Stereo.
I wouldn’t call an S350DL a great receiver but its better than most Probably due to the fact of it having a large telescopic antenna.
I use a C Crane FM transmitter with extended length on the antenna to make it between 1/4 wavelength and 1/2 wavelength.I get up to about 1,000 ft in some directions. Buildings and trees eventually get the best of the signal.
I would think range really varies by radio, and even by day.
Total posts : 45366I have a Grundig 350-DL and an original 350.
It’s not really a DX radio, but it is a very practical
radio. It works on 2 different kinds of batteries, sounds
great and loud, it has a great display, and even though
it’s not great on FM, it is good there. I would say the
AM is very good, except for some front end overload
problems. On shortwave it gets the loud stations.
I use it for WWV and CHU. Audio is very crisp and clear.
Some people say that the Grundig S-350 and S-350DL
are sort of an imitation of the famous Panasonic RF-2200.I get my C Crane transmitter on it pretty far, too.
Probably about 400 or 500 feet away.Best Wishes,
Bruce, MICRO1690/1700
Total posts : 45366Jude,
It just hit me after reading some of the other posts.
Distance was mentioned and it hit me that you did not say how far apart you and your friend are from each other.My Ramsey transmitter (fm) nearly covers the mobile home park I live in. Using Google Earth I can get a rough idea of where my signal goes and where it doesn’t even register. If line of sight is possible , my station has clear reception from 600 feet to nearly 1000 feet.
Since I am in a mobile home park, I deal with lots of obstructions.
Trees though very few, mobile homes mostly made of aluminum and steel, part of the park is elevated while the rest of it is in a hole.A hill behind my home is another obstacle , if your driving on that hill you can hear my station with some interference. Past that hill , nothing.
The only thing i have not done is ask my neighbors around me if they can hear my radio station. It is safe to say that the homes closest to mine could hear my station in their cars parked in front of their homes and maybe inside the house as well, but they would have to be the ones in front of and behind me. I have a total of 5 homes that would have unrestricted access to my signal. The rest would have to either listen in their cars or hang out the window of their homes with a set of rabbit ears on their heads lol.
So how far apart are you and your friend? What is the terrain like?
There are alot of variables to deal with when operating in the mW ranges such as part 15.My transmitter is using the whip antenna that came with it, not the outdoor antenna I built back in the Spring. So it has to pass through the siding on my mobile home to get outside.
Total posts : 45366Most of you know this, but indulge me for some who may not.
A transmitter and antenna create a signal, measured in micro-volts. Immediately it dissipates as distance is put between the transmitter and receiver.
As you move away the signal gets lower no matter what your power is, a high power FM will obviously send a receivable signal further depending on elevation to a point beyond the horizon. Wouldn’t that be nice… It behaves much like light, the trees and other houses would block light so they will also block RF, some shadow around the corners but signal gets lower very quickly when there are obstructions.
Your receive antenna and radio are the next culprits. Sometimes fancy expensive radios are not as sensitive as cheaper less feature filled units. In the Cook Islands, the Northern islands use car radios with wire antennas to receive AM radio from Rarotonga, Fiji, Tahiti or Hawaii.(or wherever.) Factory installed car radios are often great receivers because they are designed to put up with any given receive situation.
The original posting showed this very clearly; with the signal weak already, the car radio with its good antenna out of doors was picking up the signal much better than the portable indoors, take the portable outside and it may pick the signal up.
For the transmitter, elevation is everything, run audio and power wires up to where the transmitter can be, stretch the antenna vertically and your signal will improve. Then walk away and see how far it goes.
Total posts : 45366What transmitter are you using?
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