FM reception in Raymond, Wa.
Note: This page, at present, is a collection of notes I write down as I explore the condition of FM reception in my new area, and what to do (what can be done) that will improve it. Presently, these are just rough notes. My intent is that once I have a conclusion, or anything like it, I will summarize and re-write this page. For now these notes remain as evidence of my efforts.
Q:Well, what did I expect out in the middle of nowhere?
A: it is better than I might have imagined but there are some improvements in reception to be made.
This is a 3rd story flat (rented) and only indoor antennas are allowed. Period.
image 1: 1st setup with dipole antenna oriented as seen. FM reception on station 90.3 has a strong signal but also much noise in the form of sibilance. Particularly when the station broadcasts a newscast or just with spoken words. It is also present with music.
image 2: 2nd setup with dipole antenna moved and rotated horizontal result; no difference. Notice also, to the left and up on top of the rack is a Parsec Beam Booster amplified antenna that can sometimes improve on signal clarity in comparison to the dipole antenna. Also in use is a "FM Trap" from Radio Shack.
image 3: Google Earth Satellite image showing the building I'm in. To describe I could start with the terrain. To the north, east and west I am surrounded by tall hills (small mountains) that are tree covered and largely owned by the Weyerhauser corporation. This is logging country.
As I look out my balcony with a camera I can see the following:
Above: looking West out my 3rd story balcony.
image 7: Telephoto lens shot: Looking West as before but aiming the camera upward we have a view of two cell towers. These are situated on the top of a small mountain. To the North, West and East mountainous terrain such as this dominates. There is another cell tower to be found in downtown Raymond. Cell phone reception is strong in this immediate area.
Thanks to Weyerhauser, there are some modern conveniences available. For instance, I have fiber-optic communications. And that is quite modern for being situated this far away from Seattle. I have family in the Tucson, Az area and they are still stuck with copper wire (cable) internet connections. Perhaps in time fiber-optic will get out to them... or perhaps a newer technology that might just be around the corner. Meanwhile, I am trying to optimize my FM reception here at Raymond.
One particular station I want to receive:KNKX:
FM Fool map:
next; a station roll call of sorts. Using the Carver TX-11b I tune in to each of the station channels on the FM Fool list and report signal strength, genre and note reception qualities
FM Fool List for 10 Monohon Landing Rd., Raymond, Wa
new things tried:
Above: Room shot with additional antennae in use. To the left up on top of the rack is an antomotive antenna. 30 inch long stainless steel rod. Terminated with a balun to match the 75ohm input at the tuner. To the right, an inexpensive HDTV amplified antenna.
Yesterday I took a look through the box of 'stuff' I've kept over the years. This 'box of stuff' contains 'stuff' like spare coax cable, spare antennas, spare network cable, spare speaker wire (the cheaper kind that I used to use), various artifacts like coax 2-way splitters, signal amplifiers and filters. Out of this stuff I pulled a RadioShack 2-way signal amplifier designed to work with frequencies from 50 mhz to 450 mhz. (OK for FM radio which is 80.5 to 108 mhz.). Just for the heck of it, I dusted off that RadioShack FM-Trap device. (about which I know nothing). Then, having nothing to lose, I unboxed that HDTV patch antenna just to see if it might receive anything useful.
First, I found a likely spot on the wall behind the stereo rig and stuck a single skinny nail neatly into the drywall where the Pictek HDTV amplified antenna now hangs.
image 15: Secondly, I should note that this kind of antenna is tuned to receive frequencies from vhf 174 - 240mhz and UHF 470 - 862 mhz. And I should also note that this antenna is not a likely candidate for receiving FM radio signals which range from 80.5 to 108 mhz. But it did receive the signal. After some fooling around with the amplifier that comes with this hdtv antenna, I tried it with the RadioShack 2-way amplifier. The result was a signal strength of 4 lights on the tuner and an almost listenable reception. Still, there is that sibilant noise around broadcast voices and also on some of the higher frequencies of musical content. My judgement, not as good as with the dipole antenna.
I should also note that I was getting some FM signal when I had the RadioShack 2-way amp and FM Trap devices plugged into the 75 ohm input of the tuner, but without any antennas connected yet. About 3 lights on that 90.3fm station that is my target. So, the lesson here, no surprise, is that just about any kind of wire connected to the input side of a tuner can work as some sort of antenna. IT would seem that there is lots of room for experimentation there, by the way. Wire. Different lengths. Different configurations. But if you reference a book on antenna design, you can do something 'really' interesting. More about that later as I climb my way down this radio rabbit hole.
Back to the dipole
Next, having pulled out the RadioShack 2-way amplifier and FM-Trap devices, I decided to try these in combination with the dipole antenna on the wall as pictured just above for this date. Wow, that resulted in an improvement -- in terms of signal clarity and listenability. I also tried this with the FM trap inline. Best results I've heard since moving in. However I found that if I employed the multi-path reduction and noise reduction switches on the tuner, I experienced a slight but discernible improvement yet again. Better still. Almost there, it would seem. Additionally, the other stations on list #1 seemed to show noticeable improvements in listenability as well.
Should I Go Vertical?
With some discussion on the web at the Tuner forum within the Audio Asylum site, the idea had been kicked around that many FM broadcasters broadcast so that it is easy to receive their signal with your car's FM tuner. Makes sense, does it not? So, with this in mind, I took a short trip (just across the bridge) to my local Ace Hardware store in Raymond and found some goodies. Firstly I found some F-type connectors so that I can, later on, make some custom length coax cable lengths. I also found an automotive antenna, not telescopic, with a 30 inch length stainless steel round rod. This antenna will be the subject of some experimentation to come, but for now I just quickly modified the output end by clipping off the antenna plug, trimming back the insulation to reveal the bare wires and soldered these to a 75 ohm balun. Thus modified, I connected an available length of coax to the input side of the FM Trap/2-Way amp that in turn, connects to the 75 ohm input side of the tuner.
Result: 4 bars signal strength on the tuner. Some noise, sibilant, with broadcast voices. Some noise, sibilant, with upper frequency musical tones and notes. This sibilant noise is mitigated slightly by employing the noise reduction and multi-path reduction switches on the tuner.
Well, initial use of the automotive antenna doesn't bring in as much signal strength as does the dipole I have tacked up on the wall. It is, I believe slightly better: slightly cleaner sounding than I get with the Parsec Signal Booster indoor antenna, which is now back in that box of stuff I keep. Later on, I have some mods in store for a vertical antenna, which this cheaply bought antenna will undergo. But more about that later.
In the meantime
The dipole in combination with the 2-way signal amp from RadioShack, and using that little FM-Trap device (about which I know nothing) I am receiving the best yet FM radio reception. Actually, I could get used to this. But it can get better, I believe.
Vertical antenna. Automotive whip. 30 inch length. (~1/4 wave length)
goal; optimize position.
result: same signal strength but less noise. Today is sunny with no clouds. I can now listen to FM 90.3 without using the multipath reduction switch on the TX-11b tuner. Nor the noise reduction switch. This is an obvious improvement!
It has been suggested that I try a 1/2-wave folded dipole antenna fixtured to a tripod with a rotating base so that I can aim it to determine direction of max signal strength in the room.
But while doing my research I came across two different schematics for building one
Here's the first diagram: #1
It looks like a continuous open loop.
Then I found this one: diagram #2
This one is obviously different. It is described as a 1/2-wave folded dipole at:
It appears to be two separate closed loops.
Both feed to a balun where the resistance is transformed to 75ohm and offers a female coax fitting for transmission to the tuner.
Not wanting to delve too deeply into antenna theory I found it a simple matter to build both versions, try each out to see which one offers the best gain. It was this second diagram that produced the highest gain. Total length is (approximately calculated to be*) a 1/2 wavelength of the target station I am trying to receive.
I used twin-lead 300 ohm antenna wire to fabricate both antennas and then attached each one to the small frame I constructed out of 3/4wide x 1/4thick solid fir lumber. Then mounted to a small camera tripod. Both diagram versions were mounted to the same frame and are approximately equal in total length as described in the first diagram by the letter "L".
*5616/frequency in mhz = 1/2 wavelength in inches
and I am not responsible for the accuracy of the above formula. I just found it on the web as a simple and approximate tool for this task.
diagram #2: below (pair of closed loops version)
The balun came from a Channel Master model 3018 outdoor TV antenna I purchased a couple of decades ago but never used. I don't know the balun's turns-ratio. Since it came from a TV antenna and its main transmission element was a folded dipole I decided to use it.
As it turns out I saw the highest signal strength using the 2nd diagram version. Two closed loops. This antenna offers the same level, if not a little bit more than the wall mounted dipole.
It is my limited understanding that there is some directivity involved in the antenna's ability to receive. Using the rotating mount on the camera tripod I was able to turn the antenna and observe signal strength on the meter increase and decline as I turned the antenna with the tuner locked onto the target station. However this directivity does not appear to be pin-point. Rather I can turn the antenna a full 1/4 rotation without seeing the signal strength meter on the tuner change its report.
above photos: the folded dipole, with mounting frame, is nailed to the wall.
above: from just above the listening chair. The T-shaped dipole antenna is taken down and replaced by the 'folded dipole antenna'. Reason: the folded dipole antenna clearly receives with greater signal strength. All stations are coming in cleaner (less noise).
Note the six 'lit' leds indicates 'max strength' on the signal strength meter of the Carver TX-11b tuner when locked-in to the target FM station. (KNKX in the Puget Sound area) . I also receive this max read on three stations being broadcast from the Aberdeen area. Prior those were registering 4 bulbs, sometimes 5 with the store-bought dipole antenna.
I also note that until now I was not able to receive a signal from that Portland, Oregon FM station, KINK (fm 101.9). With the folded dipole the station comes in weak at 3 bulbs lit on the meter but there is a signal. Noisy, but decipherable. Clearly, this antenna offers the most gain of any I've tried so far.
re: the RadioShack signal amplifier and FM Trap devices. I find, with the folded dipole, that the FM Trap reduces signal strength. So I'm not using that with this antenna. I am feeding the signal into the RadioShack amplifier, which does boost signal strength (by how much I don't know).
I think I'll leave it like this for a while. There are other items on my agenda that need tending. However, down the road, I may try setting up a Rhombic in this room.