Post by ogrevorbis on Apr 22, 2018 22:42:23 GMT -6
So this something I had discovered in the past, but didn't realize its significance until today.
If you are driving around and listening to your radio station and hear a static noise that pops in and out every few seconds, this is probably multipath distortion.
There are two solutions: Switch to MONO. This is hard to do with a Chinese radio transmitter and this is another reason why it is better to buy the non Chinese semi-professional transmitters such as PCS. Some Chinese TXs may offer mono as an option, but I have only seen this described in the very costly units. I switched to mono today and the increase in quality was dramatic. It was at least 10x better. It sounds like I'm using much more power now, but it was just a simple fix. Multipath is apparently a problem in areas with a lot of high buildings or mountains (my area).
The other option is SSB stereo encoding. It is a different method of stereo encoding that the Stereo Tool software can produce. This may improve things a little if you want to keep your stereo, but it is not as good as just switching to mono.
I think this is a very important thing for pirates to know. My station now sounds so much more professional because there is no static popping in the background.
Post by ogrevorbis on Apr 22, 2018 22:49:38 GMT -6
I also noticed that when going from Stereo to Mono, I did not lose much. When I was in Stereo, I could only really notice its benefits when I was a mile or two from the transmitter, but beyond that the separation seemed so bad, that changing to Mono didn't really make a difference in terms of audio listen-ability.
Do yourself a favor and route a Cat 5 cable or something into the transmitter room and splice and use the cable as a control wire for various shenanigans. That's one thing I did long ago was to route the audio cable along with some spare wire out to the transmitter den, then run some relays switchable in the studio to control the RF gear or get voltage values back for remote metering in the studio like SWR and RF output or w/e, imagination time.. First thing I ever did in such a setup was a simple mono/stereo flip switch, and I did it right from my craptastic Radio Shack SSM-60 audio mixer which was my main mixdesk at the time* Thing has a built in mono/stereo toggle to blend L+R so I simply wired from that out to a remote relay to flip off the 19kHz pilot FM "HEY WE'RE IN STEREO MAKE THE LIGHT GLOW" shit.
For a bit of tech on this, though I am rather drunk, it has a lot to do with bandwidth and all kinds of other fun stuff. A monophonic FM signal requires a lot less bandwidth, and then to add less interference you don't have to worry about stereo separation circuits which get quite noisy upon weak signals. There are some stereo receivers that blend channels together progressively upon weak signal increase, but those are your select few using Pioneer Supertuners in their cars or us NAD lovers in the US using brit electrionics.
What needs to exist, and I've been thinking about this for some time is a device to automatically flip the 19kHz beacon off upon detecting monophonic content for a realistic amount of time, or rather lower the sub-carrier slowly along with detection of stereo switching over to monophonic content over a predetermined time. I always wondered if this could be made into a piece of real broadcast gear, but it's still not making up for the receivers end. At the end of the day put a switch in the studio, if the DJ or talk host (probably you) knows you are going to be playing mostly monophonic or talk content, then flip the switch to control the transmitter to do your bidding. Just be warned that people with car radios made before 1983 and 1/3 are going to realize you are broadcasting in NPR "stereo"
*Give me a break, I upgraded the OP AMPs in the bitch and put sexy back lighting behind the Vu meters, that counts right? If you haven't broadslutted through a Radio Shack mixer you aren't cool enough for the lower sideband club.
Do yourself a favor and route a Cat 5 cable or something into the transmitter room and splice and use the cable as a control wire for various shenanigans. That's one thing I did long ago was to route the audio cable along with some spare wire out to the transmitter den, then run some relays switchable in the studio to control the RF gear or get voltage values back for remote metering in the studio like SWR and RF output or w/e, imagination time.. First thing I ever did in such a setup was a simple mono/stereo flip switch, and I did it right from my craptastic Radio Shack SSM-60 audio mixer which was my main mixdesk at the time* Thing has a built in mono/stereo toggle to blend L+R so I simply wired from that out to a remote relay to flip off the 19kHz pilot FM "HEY WE'RE IN STEREO MAKE THE LIGHT GLOW" shit.
For a bit of tech on this, though I am rather drunk, it has a lot to do with bandwidth and all kinds of other fun stuff. A monophonic FM signal requires a lot less bandwidth, and then to add less interference you don't have to worry about stereo separation circuits which get quite noisy upon weak signals. There are some stereo receivers that blend channels together progressively upon weak signal increase, but those are your select few using Pioneer Supertuners in their cars or us NAD lovers in the US using brit electrionics.
What needs to exist, and I've been thinking about this for some time is a device to automatically flip the 19kHz beacon off upon detecting monophonic content for a realistic amount of time, or rather lower the sub-carrier slowly along with detection of stereo switching over to monophonic content over a predetermined time. I always wondered if this could be made into a piece of real broadcast gear, but it's still not making up for the receivers end. At the end of the day put a switch in the studio, if the DJ or talk host (probably you) knows you are going to be playing mostly monophonic or talk content, then flip the switch to control the transmitter to do your bidding. Just be warned that people with car radios made before 1983 and 1/3 are going to realize you are broadcasting in NPR "stereo"
*Give me a break, I upgraded the OP AMPs in the bitch and put sexy back lighting behind the Vu meters, that counts right? If you haven't broadslutted through a Radio Shack mixer you aren't cool enough for the lower sideband club.
This is a good idea. I especially like the use of twisted pair wire like in the ethernet cable to use as control wire. I think this may be helpful for some, but I don't think I'm ever going to use Stereo again (in this area). It really is a night and day difference - for music too.
What do you mean by NPR stereo? Are they using SSB or are they trying to mimic stereo with fake audio surround sound tricks?
Lol I was joking about NPR since stations carrying them are usually known to run stereo even though the content of many shows is mono, or the other way around.. depending on the station. Some stations flat out refuse to turn the stereo pilot off because they don't want listeners thinking their broadcast is of "lesser quality".
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