I was playing back an edited recording at 101.9 FM, an auxiliary channel here, as the main stream broadcast is on other frequencies. Using a C.Crane that works fine indoors, I wanted to be out on the porch enjoying the better temperatures, but right out the door the Grundig FR200 lost the signal and came up with only noise pollution from all the high power stations.
Here is my bold idea. I believe it would help to have a very low power booster amp to get the FM just strong enough to get out there, realizing that the house itself is an attenuator. This should be safe as long as the 200-foot limit is carefully observed.
I know the “voiding the certification” situation, but there is an alternate rule which allows up to a certain power out there at a certain distance, and 200-feet seems to be the safety zone.
Is this idea within reason, or is it totally irresponsible.
Infrequent use
Seriously…I do not think that adding a bit of boost now and then just to get a bit more signal out the door is being irresponsible. In my opinion worrying about if its irresponsible or not to have the signal reach outside for a couple hours or so is taking worry a bit to the extreme….as is worrying about voiding certification.
Now if you slap a fat amp and multi antenna on a 50 foot tower and shoot the air 24/7…then at that point the worry would be come valid as well as validate irresponsible and void certification.
Its not as if your purposely intending to shoot a seriously “over the limit” signal.
What I wonder is why your C-Crane unit isnt sending the signal well enough through the house to outdoors into the yard. Those things should be able to do that with no problem….unless the distance between the Crane unit and the outdoor patio furniture is well beyond 200 feet. Those things, as well as other certified FM units can and will send a signal beyond 200 feet.
If I recall, those C-Crane units have a pot in there that will adjust its output. Open it up, mark the current position of the pot, then turn it up a bit and check the radio outside for a decent signal, and mark that new position with a different color marker.
Then when the outdoor fun is done, reset the adjustment back to its original position. Doing so will avoid having to mess with using any kind of amplifier, attenuated or not, as well as avoid altering the C-Crane unit so extensively to attach an amp, which at that point you DO void certification.
Or run a much longer audio lead to the C-Crane unit and relocate that closer to where you need its signal.
RFB
Probably Longer Audio
Your point of view probably gives a better plan of action, RFburns, than going to the trouble of building an amp, namely a longer audio lead to put the transmitter right in the window.
I already peaked that internal adjustment in the Crane and it made a very slight improvement.
This building must be a Faraday shield because signals don’t want to go through the walls.
On the other hand the auto radio hears the FM from the Crane almost as well as the AM at 1680.
Part 15 gives no rest even though we’re not wicked.
Faraday cage/house
This building must be a Faraday shield because signals don’t want to go through the walls.
I recall some buildings would have a layer of chicken fence wire in the walls to help prevent the insulation from sagging after a few years. Usually these are not grounded but somewhere at some point it could be grounded from a nail or screw pinching on one little wire of the chicken fence wire and turn the entire thing into that Faraday cage.
Also the car radio will be far more sensitive than the radio your using, and is probably why it can detect the signal where the C-Crane unit is normally located.
Part 15 gives no rest even though we’re not wicked.
True…it is done on purpose. The limits are set so that we are buried in with the noise floor. Only on rare occasions and right conditions does that noise floor drop low enough to make our signals well noticed beyond the set limitations.
Fortunately radio receivers, some of them anyway, are equipped with very tight Intermediate Frequency front ends and sport noise canceling circuits to help notch out those annoying noise floor spikes. Such front ends are found in car radios and expensive in-door radios such as that found in the HAM realms and high-end consumer hi-fi stereo systems.
RFB