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Musicradio 1300
- Thread starter ContinuousWave
- Start date
F
First Fone 65
Guest
Liberty,That is a fact, more noise, less ground conductivity, longer day light hours, ask any Ham who has operated 160 Meters 1.8 to 2.0 MHZ just above the am broadcast band and they will tell you late fall and winter is the best time for the low bands,
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rbrucecarter5
Guest
Careful Joe! The last time I said that, I got attacked mercilessly! In spite of having the best test station in the world - KGLK - which alternated between on and off for a couple of years while I was driving to and from Dallas. The difference in coverage was close to 60 miles! But - in all seriousness - after talking with people on the board, I think it was a change in antenna bay type - and not the presence of HD sidebands - that caused the difference. Whatever bays they changed to - and most of the stations in Houston changed to - are JUNK! HD FM stations don't have to use them, and in fact I have an excellent example of a station that does HD without compromising range - KBPA. I had them on my presets, because in West Houston they were almost like a local. I still have the same preset, just for Cypress radio now. And if I miss KBPA, on a lot of mornings, they clobber Cypress radio. Before Cypress radio, most mornings KBPA HD came in. Of course that is on a decent car radio with a real whip antenna, but I was impressed.
I think I busted that myth about C-Quam limiting a station's range when I took a Sony SRF-A1 out to the Crosbyton Canyon, 290 miles from Dallas, and had KMKI and KAAM in perfect, static free C-Quam. I even walked around the canyon a bit seeing if I could get platform motion off the canyon walls. I couldn't. Only rattlesnakes deterred me from testing further. The only hint of platform motion was on KAAM, but that had more to do with KKOB being under it than it did with the Canyon walls. The main proponent of that theory about C-Quam limiting range was talking about Los Angeles, and there are other factors out there like the size of the mountains that limit AM range with or without C-Quam. 290 mile static free AM stereo is impressive from a 5 kW regional any way you look at things. Unfortunately both stations succumbed to the siren call of HD AM, and I really DID notice a drop in range with C-Quam. Especially with a daughter who was really into radio Disney and nagging me about "why isn't it working as well" " why does it have static now" "why does it sound bad" on visits to Lubbock. UGH! Made me want to strangle a station owner who changed to that kludgy HD system, or give their number to my daughter and let her nag them instead of me!
Cquam does not affect the range of an AM station.. It's been shown over and over since Kahn tried to use that argument decades ago.
F
First Fone 65
Guest
CW. How many stations still use CQuam ? I have a old 1988 S10 that has it in it, I remember I thought it sounded as good or better than FM stereo at the time, but was very pricy just happened to come with the equipment package in My truck, I would not have paid the high dollars they wanted for the AM stereo radio.
Because you were wrong then as you are now.
The brand of an FM antenna and even the model in a particular brand can make a major difference. So can proper beam tilt for very high towers or sites. But HD is not a factor.
That's bogus because platform motion was fixed long ago, and when it was still a factor it was noticeable and nauseating in moving vehicles, not when walking around with a portable radio.
Where's a good rattlesnake when you need one?
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rbrucecarter5
Guest
Really? You wish I would get bitten by a rattlesnake?
I still think platform motion is a function of a distant carrier, on a slightly different frequency, than it is inherent in the C-Quam system. I know as I tested, KKOB was causing the channels on KAAM to slowly reverse left to right, right to left. I suppose that could a person sick to the stomach, but if so - I wouldn't listen to "All Along the Watchtower" where it was done intentionally.
What does make me a bit queezy is listening to HD AM for any length of time. The compression artifacts, particularly on music stations, are awful. That is also the reason I didn't listen to streaming audio on a modem. The digital artifacts on HD AM remind me of high bandwidth streaming that has problems. Not pleasant to listen to.
Science is based on observations, and my observations on KGLK were repeatable. HD on - they were gone by Huntsville. HD off - the made it to Centerville. Not that they care, as you have pointed out. But bad range also means weaker signal where it DOES matter. But I am willing to concede that it may be that they were switching between antenna bays as well as turning HD on and off - something that is supported by the excellent range of the San Marcos station. So I will agree with you - if there are no other changes (such as antenna bays) HD has no effect on range.
I do notice that KRBE has had no HD for a few days, it would be interesting to do a drive test and see if it has any more range. If they are still using the same bay they use for HD, there shouldn't be. It is a real shame that Houston station are using inferior antenna bays. I used to enjoy getting KRBE in Louisiana once the station in Houma faded on road trips. My first welcome back to Texas - by the time I crossed the border it was like a local. It was also nice to hear it in Austin when I went to college there. It had an amazing range - not sure what got goofed up, but the antenna bays would be a prime suspect.
I still think platform motion is a function of a distant carrier, on a slightly different frequency, than it is inherent in the C-Quam system. I know as I tested, KKOB was causing the channels on KAAM to slowly reverse left to right, right to left. I suppose that could a person sick to the stomach, but if so - I wouldn't listen to "All Along the Watchtower" where it was done intentionally.
What does make me a bit queezy is listening to HD AM for any length of time. The compression artifacts, particularly on music stations, are awful. That is also the reason I didn't listen to streaming audio on a modem. The digital artifacts on HD AM remind me of high bandwidth streaming that has problems. Not pleasant to listen to.
Science is based on observations, and my observations on KGLK were repeatable. HD on - they were gone by Huntsville. HD off - the made it to Centerville. Not that they care, as you have pointed out. But bad range also means weaker signal where it DOES matter. But I am willing to concede that it may be that they were switching between antenna bays as well as turning HD on and off - something that is supported by the excellent range of the San Marcos station. So I will agree with you - if there are no other changes (such as antenna bays) HD has no effect on range.
I do notice that KRBE has had no HD for a few days, it would be interesting to do a drive test and see if it has any more range. If they are still using the same bay they use for HD, there shouldn't be. It is a real shame that Houston station are using inferior antenna bays. I used to enjoy getting KRBE in Louisiana once the station in Houma faded on road trips. My first welcome back to Texas - by the time I crossed the border it was like a local. It was also nice to hear it in Austin when I went to college there. It had an amazing range - not sure what got goofed up, but the antenna bays would be a prime suspect.
F
First Fone 65
Guest
WTAW AM, HD 1620 kHZ college station is the only AM HD I can hear, and most of the time signal too weak for HD to lock, but sounds pretty good when I can receive it.
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rbrucecarter5
Guest
Yes, they are HD. Not that HD or stereo matters for their format. I used to get them in HD up and down Fry Road and down Tuckerton, but the moment they erected power lines by the road, HD won't lock any more.
There have been a few antenna changes over the years.
Also, sometimes when a station isn't running their HD it's because they are running from an aux site.
But generally speaking, stations are more interested in putting as much signal into the most populated areas of the market and not sparsely populated towns on the fringe.
But Bruce's observations remind me of the time an engineer I know let the PD adjust the processing while it was bypassed. The guy drove around for weeks "getting the sound just right" and there was no convincing him that it was patched out after the engineer and GM came clean.
Humorless much?
The manufacturer introduced a patch which cured the problem. Were it an issue of distant carriers of multipath (on AM... really?), it would not be fixable.
It definitely could be nauseating. I recall driving the KTNQ signal in LA with our chief engineer and having to stop so he could get out of the car and throw up. We were in the flattest part of the LA basin in the middle of the roughly 300 kw major lobe of the station, by the way.
Have you considered that when the HD was off, they may have been on a different transmitter and even, perhaps, a different antenna? I do not know their installation, but I am familiar with stations that have multiple transmitter and antenna possibilities for backup.
An auxiliary antenna may not have the proper or needed beam tilt and may have a different radiation pattern if it has fewer or more bays. Unless we know if we are comparing the same antenna and transmitter combination, there is no way for you to reach conclusions.
Stations can not switch on individual bays in an FM antenna. FM antennas are sets of bays, fed from a common point, and the bays are not individually addressable.
Unless you know if they are using the same antenna, the experiment is useless.
A "bay" is an element in an FM transmission antenna. Multiple bays (as well as inter-bay spacing) determine the amount of gain. Beam tilt determines the angle of the horizontal lobe, and parasitic elements can be used to directionalize an antenna.
There are only a couple of manufacturers of FM antennas left. But there are different models from each. Here is the page for my preferred vendor, ERI:
http://www.eriinc.com/Catalog/Antennas/FM-Antennas.aspx
Note that there are different power handling capabilities and characteristics all from the same company. Of course, a station may choose a different model for an auxiliary antenna due to where it will mount on the tower and how many bays can be accommodated (aux antennas are often fewer bays for space, cost and wind load reasons. They are generally lower on the tower).
What you call "inferior" may in fact be a superior antenna with beam tilt that does not send as much power towards the horizon and gets a better signal closer in to the antenna.
Outside of the 5mv/m contour.... Sounds great on my stereo rcvr in Bmt
Originally it was proposed they run Cquam but by the time the exband took off, Cquam had fallen out of favor
U
Unknowable
Guest
I think Chris is working on it.
Still working on the stream.....new processor on air now...sounds great!!
KLLS suffered a failure of the automation PC last night so its off the air for repairs...HOPE to have it back this weekend....New Orban processor was added in the last two weeks...BIG improvement on audio loudness and density....and FANTASTIC in stereo!
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rbrucecarter5
Guest
I going to go for it with a Hammarlund SP-600JX - probably the most sensitive AM radio ever made. With an 8 foot loop to throw a null at Austin. I don't know when I will get the setup going, but we will see if 1300 comes in far West Houston.
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