HELP – ANYONE!
The AM Transmission signal from a PROCRASTOR unit seems to drop-off completely after about 25-35 yards! Hardly half a block, a far cry from the 1/2 mile to 2 mile reach.
HELP – ANYONE!
The AM Transmission signal from a PROCRASTOR unit seems to drop-off completely after about 25-35 yards! Hardly half a block, a far cry from the 1/2 mile to 2 mile reach.
Does anyone have experience with this unit, or an idea about what the issues could be?
Thanks in advance.
Lots of reasons
The usual culprits are:
1) Improper tuning. The signal must be tuned to resonance for the given frequency. It takes some work and time, an exacting trial. Also, the higher the frequency, the easier it is to get a good signal match that will get out, so find an empty frequency above 1500 kHz.
2) Poor or non-existent grounding. Best ground you can achieve is critical to getting out with AM radio because it propagates via ground wave (daytime). In fact, I’d say it’s one of the most-discussed topics on this forum.
… but there are many other things, such as mounting position and environment (e.g., next to metal siding is bad), surrounding structures, RFI on the frequency, elevation, wire connections, the list goes on.
In order to help, we need info about your installation.
That transmitter had no
That transmitter had no problem making a mile at 12ft above ground with a decent ground.
Make sure you tune it right and give it a good ground.
http://www.xrqk.com/RADIOBRANDYNET/MicroBroadcasters.html
Meter should be as shown here; also note what kind of radio you are using to test with. Some radios have really poor AM sections.
Steve
http://www.radiobrandy.net
Ground
I’d say this could be the result of either a bad location, or a poor ground.
Where is the Transmitter placed?
What is it grounded to?
TESTING – AM Transmitter
HEY EVERYONE!
DISCLAIMER — ***Be Kind*** THIS IS STEP ONE OF TESTING/PLACEMENT PHASE!
Here are a few vids to give you a clearer idea about today’s part 15 transmitter test. Thanks in advance for the feedback:
Video Part 1 (Transmitter “test” set-up & terrain view): http://www.viddler.com/explore/Commander_VID/videos/5/?secreturl=40929384
Video Part 2 (Transmitter “test” set-up & terrain view): http://www.viddler.com/explore/Commander_VID/videos/6/?secreturl=57823360
PS – A 10ft copper grounding rod can be installed when a permanent mounting of the transmitter is done. How effective will the mesh radial grounding kit be for the terrain in our video? The DXE-RADP-1P Radial plate sold at DX engineering (http://www.dxengineering.com/Parts.asp?ID=4866&PLID=208&SecID=110&DeptID=32&PartNo=DXE-RADP-3)
Secondly, a part 15 FM transmitter was able to be picked up for 2-3 blocks with a SENTRY portable radio (an MBRC model as pictured).
Is there any hope for an AM portable radio sensitive enough to pick up the transmission signal for 2 – 4 blocks or more?
J.C.
Put it this way…
My transmitter is mounted on a boat in an ocean marina. Best ground/counterpoise you can have. On a good day my signal sounds great at a mile or so out on a good car radio (the test vehicle s a 1997 Chev Astrovan), then it begins to get signs of static … but not much until it gets to 1.5-2 miles. After that it steadily gets worse until you can’t hear anything but static.
Some very good days, talk, like an OTR program, say a clean episode of “The Shadow”, can be heard and understood as far out as Egg Lake Road, a bit more than 3 miles.
However, a ham radio friend showed me @ S8 on his General Communications Receiver more than 8 miles away! BUT, that’s with a very expensive top-of-the-line Icom receiver with filters, frequency adjustable preamps, and a longwire rhombic antenna pointed generally my direction … which just goes to show what a difference the receiver can make. I have never heard my station out there where he is.
Also, right in the downtown area of my small town, which is the intended coverage area, it’s tough to get it inside a building … but then so is everything else: other buildings, wiring, florescent lights, neon lights, automobile ignition systems, power line junctions, etc.
After dark, there is often so much skywave interference, it gets noisy for 6 hours at a time.
That’s AM radio for ya 😉
MORE AM TRANSMITTER TEST VIDEOS
Wow Ken,
The tips about your AM radio transmitter results sound fascinating. That’s great information about receivers in cars, radios, and CB receivers.
Based on your explanation it sounds like our test are going to include some in building tests as well.
Once we determine a permanent location on the hill top a copper ground wire will be installed for best range performance (according to Procastor transmitter maker Chez Radio).
Here is the complete 5 part short videos of the 3 block radius test of the Procastor AM transmitter on a hilltop and tree filled terrain. Enjoy and share the videos with others!
VIDEO 1: http://www.viddler.com/explore/Commander_VID/videos/5/?secreturl=40929384
VIDEO 2 http://www.viddler.com/explore/Commander_VID/videos/6/?secreturl=57823360
VIDEO 3: http://www.viddler.com/explore/Commander_VID/videos/7/?secreturl=48792365
VIDEO 4: http://www.viddler.com/explore/Commander_VID/videos/8/?secreturl=29603972
VIDEO 5: http://www.viddler.com/explore/Commander_VID/videos/9/?secreturl=24488466
Trash cans make for a poor
Trash cans make for a poor ground system; try to find a water faucet to clamp on to. Does the vehicle have a vertical rod antenna?
Make sure element is clear of building and does not touch ladder. I also noticed power lines which can drown out the signal too.
Steve
http://www.radiooutlaw.com
Far Out!
Hey Ken,
I have been curious for some time now, how far out on the water has your station been heard? I see potential for DX’ing here. Maybe a new dx record?
Water Table
The summer heat is causing brain lightning that normal doesn’t happen, but speaking of the good RF ground conductivity of water I stated thinking about the water underfoot known as “the water table.”
On the one hand I think antenna ground needs to be right at the surface and not buried too far down, what if surface radials were ground rodded down into the water table at many points?
Nobel Prize?
That heat wave!
The heat I hear about that most folks are dealing with sounds almost incomprehensible – just awful!!!
We’ve yet to break 75 up here in the fourth corner and we were gonna get upset about having a lousy summer until we tuned in the national weather report – sheesh!!!
Water table transmitting sounds interesting – I swear I tapped into that when I was in Vancouver, WA – my ground rod touched a drainage pond that was connected to a rainwater drainage culvert than went for several miles and I could tune my station in along the entire length of the culvert whenever it rained – which is almost continuously up here 🙂
That heat wave!
The heat I hear about that most folks are dealing with sounds almost incomprehensible – just awful!!!
We’ve yet to break 75 up here in the fourth corner and we were gonna get upset about having a lousy summer until we tuned in the national weather report – sheesh!!!
Water table transmitting sounds interesting – I swear I tapped into that when I was in Vancouver, WA – my ground rod touched a drainage pond that was connected to a rainwater drainage culvert than went for several miles and I could tune my station in along the entire length of the culvert whenever it rained – which is almost continuously up here 🙂
i tried to go onto AM
a couple of years back i bought me a radio systems I AM Transmitter to compliment the fm station i already had at 88.7 so i put the am station @ 670 AM Sunrise-Sunset daytimer Station. i eventually gave up the am for 2 reasons the ground was horrible, even with it grounded still nothing. and the ground is so sticky and hard and no good soil for it to do its magic and i have seen houses crippled and trashed because of the ground and the tremors (small earthquakes) in oklahoma State can cause that too (the ground) to be so bad, so grayson county texas and nearby the red river bordering texas and oklahome is not a good place to start a part 15 AM radio station because i have tried and got tired of it evetually. so FM Seems the way to get singal out here in my neck of the woods!