Transmitter Only Sounds Good During Day

[Bob Musil]

I am extremely frustrated right now. During the day, my FM transmission is very clear, and the range is excellent. At night, it sounds like garbage before I get out of my driveway.

Background info - We live on the eastern slope of the Sierra Nevada range, and have been having strong winds lately. This is a rural area, so there is no problem with interference from commercial stations. I have one of the China/e-bay transmitters (might be Hlly, I can't find the manufacturer's name on it) connected to a Ramsey FMA200 antenna. The transmitter is about 4 feet from the computer, sitting on top of a metal file cabinet. I don't know if it makes any difference, but we are transmitting at 94.1.

Any advice or suggestions would be greatly appreciated.

[JBullard]

I don't have an answer for you, but I have seen similar posts on other boards from users of China/ebay transmitters.

Is the Ramsey antenna inside or outside the house?

Just a suggestion for next year, maybe considering upgrading the transmitter to an EDM

[Bob Musil]

JBullard wrote:

Is the Ramsey antenna inside or outside the house?

The antenna is outside the house. It is mounted against one of the eaves, and high enough that the lateral lines are not touching the roof.

[Max-Paul]

You are experiencing a typical day to night problem. It seems that there is a transmission that appears at night from a distant transmitter. Better known as night skip. This station is skipping into your area at night. Shut down your transmitter and go out to your driveway and listen to your car's radio on the frequency you transmit on. I bet you hear a distant transmitter either on your frequency or a frequency up one or down one adjustment. Looks like you are going to need to select a different frequency.. Make this selection by listening to what is out there at night.

[greenie95125]

Bob Musil wrote:

I am extremely frustrated right now. During the day, my FM transmission is very clear, and the range is excellent. At night, it sounds like garbage before I get out of my driveway.

Background info - We live on the eastern slope of the Sierra Nevada range, and have been having strong winds lately. This is a rural area, so there is no problem with interference from commercial stations. I have one of the China/e-bay transmitters (might be Hlly, I can't find the manufacturer's name on it) connected to a Ramsey FMA200 antenna. The transmitter is about 4 feet from the computer, sitting on top of a metal file cabinet. I don't know if it makes any difference, but we are transmitting at 94.1.

Any advice or suggestions would be greatly appreciated.

Are you running the transmitter all day? I'm just wondering if it's overheating by the time night rolls around. If it's overheating, it would normally do so pretty quickly, and your final would be fried. Those chinese transmitters have no protection against overheaing.

Cheap transmitter or not, it's an odd symptom you're describing. SWR going thru the roof will cause those symptoms, but it wouldn't be limited to night time. Does ANYTHING change in the evening around the antenna? Like a garage door open or closed, or a metal gate?

I'd also get the transmitter off of the metal cabinet. I don't think it's causing your problem, but it's certainly not going to help.

--Mike

[greenie95125]

Sorry for the dbl post. Not sure what happened.

I thought about the night-skip problem that Paul mentioned, but that is more prevalent with AM signals than FM signals. Not that it cannot happen, it's just not common due to the polarity of the transmitting antenna. I'd definitely heed his advice though, and have a listen at night on your broadcasting freq.

--Mike

[Guest guest]

Anyone near you that could possibly also be doing a LOR (or similar) show using the same freq?

If not an interferer of some sort, definitely would be interesting to see if you had the same problem both when the transmitter was powered up all day, versus left off.

And of course, the quick and dirty test is just choose a new freq tonite to use...

[Bob Musil]

I will try a different station tonight, and post the results.

I powered down the transmitter for today. I have been leaving it on 24/7, so maybe it has something to do with my problem. I will also move it off of the file cabinet, although that will mean it will be closer to the computer. Will this cause any other problems?

Nothing changes near the transmitter or the antenna from day to night, so that is out. Same thing with other users of LOR or similar products. The closest I know of is almost 50 miles away. There may be someone in town about 35 miles away, but I am certain there is nobody within 10 miles of me.

Thanks very much for the suggestions. I will try them tonight.

[Max-Paul]

greenie95125 wrote:

Sorry for the dbl post. Not sure what happened.

I thought about the night-skip problem that Paul mentioned, but that is more prevalent with AM signals than FM signals. Not that it cannot happen, it's just not common due to the polarity of the transmitting antenna. I'd definitely heed his advice though, and have a listen at night on your broadcasting freq.

--Mike

mike you got to be kidding right? I mean what is this B.S. about polarity? Both use vertical polarity for a omni dirctional radiation pattern. This is broadcast not military or Amateur Radio where you want to beam a signal to a certain area. Ok, Commerical would also want to beam for a link between sites. And if you know anything about skip, then you would understand why Hams have different bands in the HF range. Cause certain bands are better during the day and other at night. Also the seasons effect the ability to "Skip". Heck I talked to Ohio one morning on 2 mtrs (144 Mhz) with just 25 watts. So what does FM have to do with skip? BTW our 2 mtr rigs are FM.

Mike I slapped you down because I am tired of all this jabber by people who for the first time in their life operated a transmitter that is connected to their Christmas light show. Have never read a book about transmitters and propagation. Dont have a Amateur radio Lic or what was known as the Radio Telephone Lic. (can work on commercial radios). But sure do know how to drop some 25 dollar words.

[Guest guest]

Bob Musil wrote:

I will try a different station tonight, and post the results.

I powered down the transmitter for today. I have been leaving it on 24/7, so maybe it has something to do with my problem. I will also move it off of the file cabinet, although that will mean it will be closer to the computer. Will this cause any other problems?

Nothing changes near the transmitter or the antenna from day to night, so that is out. Same thing with other users of LOR or similar products. The closest I know of is almost 50 miles away. There may be someone in town about 35 miles away, but I am certain there is nobody within 10 miles of me.

Thanks very much for the suggestions. I will try them tonight.

So if it is on 24/7, and if it has a component with a thermal issue, it won't have issues during the night, then clear during the day, unless you have some major ambient temp changes around the transmitter during the day. If you said you turn it off, and then after X hours of operating, it tends to always have issues, that would point more towards a transmitter issue.

To qualify my comments, for others who have posted (), I have both an extra class amateur license, and a commercial license (for what its worth anymore..), and 25+ years in the wireless/telecom biz in various engineering/technical roles...:shock:

Even then, I won't wade into the broadcaster polarization debate..the broadcasters have been futzing with horizontal, vertical, and circular polarization since the days of Marconi and Armstrong..

Will be real curious to see what your testing shows tonite..keep us posted.

[George Cotton]

This is my current LOR electrical supply setup.

Main power is controlled by the switch at top right. In the center is a GFI that protects everything downstream which is on when the switch is on. Next is a timer I bought at Lowes. It's set to turn the recepticals below on 5 minutes before showtime and off about 5 minutes after. Since virtually all of my lights are now LED's, the current load is not a problem.

This timer turns on power to the controllers, the FM transmitter and the night light to indicate power is there and a reminder that the controllers are HOT (electrically - don't let fingers stray).


Attached files

[greenie95125]

Max-Paul wrote:

greenie95125 wrote:

Sorry for the dbl post. Not sure what happened.

I thought about the night-skip problem that Paul mentioned, but that is more prevalent with AM signals than FM signals. Not that it cannot happen, it's just not common due to the polarity of the transmitting antenna. I'd definitely heed his advice though, and have a listen at night on your broadcasting freq.

--Mike

mike you got to be kidding right? I mean what is this B.S. about polarity? Both use vertical polarity for a omni dirctional radiation pattern. This is broadcast not military or Amateur Radio where you want to beam a signal to a certain area. Ok, Commerical would also want to beam for a link between sites. And if you know anything about skip, then you would understand why Hams have different bands in the HF range. Cause certain bands are better during the day and other at night. Also the seasons effect the ability to "Skip". Heck I talked to Ohio one morning on 2 mtrs (144 Mhz) with just 25 watts. So what does FM have to do with skip? BTW our 2 mtr rigs are FM.

Mike I slapped you down because I am tired of all this jabber by people who for the first time in their life operated a transmitter that is connected to their Christmas light show. Have never read a book about transmitters and propagation. Dont have a Amateur radio Lic or what was known as the Radio Telephone Lic. (can work on commercial radios). But sure do know how to drop some 25 dollar words.

I got it, if you aint a HAM, you know nothing. My bad for using the wrong word (polarization instead of propagation). I am humbled by your slapping.

Modulation has nothing at all to do with skip, but frequency does. In GENERAL lower frequencies (AM band) are more likely to skip than higher frequecies (FM band).

Being a pilot, I have no need to know anything about radios . Consider this, if our VHF radios (voice or nav) skipped at night, what do you think ATC would be like?

--Mike

[Max-Paul]

Ok all that you just posted is true to a degree. yes higher frequencies do not skip as frequently as the lower frequencies. But it appears that you have not listened to your F.M. receiver as much as I have and I have seen on regular bases that at night you will hear F.M. stations that you can not hear during the day.

As for your VHF radios that you use in aircraft and ATC. I dont suppose this might have any reason that you are handed off to different frequencies as you travel across the nation? I dont really know, but wonder how many times a given frequency is re-used across the nation. I would suspect that it is not often. And I bet your radio has something that broadcast radios do not. Tell me, does your radio have a thing called squelch? And you care to tell everyone here what squelch is used for? I think your mixing of apples and oranges are about to blow up in your face.

And for your information, if I was just a C.B. op and know what I am talking about. It appears that I am still talking circles around you. Best back off, your out of your league on this subject.

I really hate to do this, but I just will not sit back and let someone that knows nothing about radios other than how to key the mike tell half truths. Cause there is a difference between polarization and propagation.

In short, Mike you are a highly educated person that knows far more about flying. But between the two of us, you dont know jack about transmitters and radios in general. Please keep your nose in the cockpit and let me handle the radio questions between the two of us. I know that there are a few others who work with radios or have taken test that prove we know something about transceivers other than how to key the mike and adjust the squelch. Your knowledge is limited at best. Get a Amateur Radio Lic of Advance class or greater and I will be willing to listen to what you have to say. Remember Amateur radio operators have made it possible for some forms of modern communication.

[greenie95125]

Max-Paul wrote:

Ok all that you just posted is true to a degree. yes higher frequencies do not skip as frequently as the lower frequencies. But it appears that you have not listened to your F.M. receiver as much as I have and I have seen on regular bases that at night you will hear F.M. stations that you can not hear during the day.

As for your VHF radios that you use in aircraft and ATC. I dont suppose this might have any reason that you are handed off to different frequencies as you travel across the nation? I dont really know, but wonder how many times a given frequency is re-used across the nation. I would suspect that it is not often. And I bet your radio has something that broadcast radios do not. Tell me, does your radio have a thing called squelch? And you care to tell everyone here what squelch is used for? I think your mixing of apples and oranges are about to blow up in your face.

And for your information, if I was just a C.B. op and know what I am talking about. It appears that I am still talking circles around you. Best back off, your out of your league on this subject.

I really hate to do this, but I just will not sit back and let someone that knows nothing about radios other than how to key the mike tell half truths. Cause there is a difference between polarization and radiation pattern although they also go hand in hand. But anyway you slice it or dice it. A horz antenna is going to be directional and a broadcast radio transmitter is going to want to reach as many people as they can and so they will use a vertical omni antenna. So there is no difference between AM and FM in that manner.

If we all knew 1/2 as much as you, the world would be a much smarter place, eh? I'm sorry we mere mortals offend you so when we mis-use a term.

Then the scramble to attempt to show your superiority... wow.

OK, I will now use my squelch knob right here and now, so I don't need to read anymore of your diatribes. I'm done with you.


Happy Holidays.

--Mike

[chuckd]

Just to throw in a non-technical two cents. I am using a Broadcast Warehouse TX1 transmitter with a nice antenna, and my range at night is about half what it is during the day. This happens every day without fail. It's not a problem for me since I'm still very clear, but I would have to say it's definitely an atmospheric phenomenon. It's also unrelated to temperature, since 30 degree nights and 60 degree nights are about the same.

At night, I can pick up a low power station on my frequency that's about 70 miles away. During the day, I can't pick them up at all.

My old Ramsey FM100 did this exact same thing day/night.


Edit: reviewing an old engineering textbook, this is definitely related to the ionosphere and the sun's effects on wave propagation. Medium to short wave transmissions typically transmit significantly longer at night, so I'm betting our limited distance is due to interference from stations that simply don't make it to our area during the daytime. I guess I'm agreeing with Max-Paul.

[Bob Musil]

Well, here is tonight's update. I unplugged the transmitter all day, and moved it off of the metal file cabinet. Still too much static this evening. I moved the channel from 94.1 to 93.9, and it made no noticeable difference.

Monday (weather permitting) I am going to change from the lower end of the spectrum up to the high end, maybe around 103. I can't do this at night, because it involves changing the length of the antenna. Is there a difference in the "skip factor" at different ends of the FM spectrum?

I REALLY appreciate all of the information you folks are providing. I am half-way decent with a computer, but I know next to nothing about power issues, and less than nothing about radio and transmission.

Bob

[J_Plak]

Bob, some question for you, What type of Cable are you using between the transmitter & antenna and what are your Temperature dunring the day then nights ?

[Bob Musil]

J_Plak wrote:

Bob, some question for you, What type of Cable are you using between the transmitter & antenna and what are your Temperature dunring the day then nights ?

I am running 30 feet of RG-58 (2 sections with a connector), with PL-259 connectors.

As far as temperatures, the last few days have been in the high 40's/low 50's, and the nights have been in the 20's.

[RaceMedic]

Bob Musil wrote:

I am running 30 feet of RG-58 (2 sections with a connector), with PL-259 connectors.

My uneducated guess would be to look at the connectors ?!

I had a similar problem going from my PC to by MBB 4000 ... Anywhere that you have a connection can cause problems.

Dave

[J_Plak]

I also would be to look at the connectors also take a very close look at the connector at the 2 sections connectors thinking you maybe using a coupler ?

As far as temperatures during the cable maybe freezing if any moisture is in the cable..
RaceMedic wrote:

Bob Musil wrote:

I am running 30 feet of RG-58 (2 sections with a connector), with PL-259 connectors.

My uneducated guess would be to look at the connectors ?!

I had a similar problem going from my PC to by MBB 4000 ... Anywhere that you have a connection can cause problems.

Dave