OK, I stand by my statements and their relevance.? If you want to make it an argument about something else, That's you.?
My main point was bandwidth of the RF signal, which directly relates to the maximum frequency of modulation and the
deviation.? If you don't think the bandwidth of the emitted RF signal on 2m matters? OK.? If you think it doesn't matter on
440 either?? OK.? If you think operations other than what you are interested in don't matter? OK, that's on you.?
It would seem that K6OQK (OP) understood me and seems to care enough to address the issue as much as possible with
proper and careful audio processing.? The key to audio quality is to avoid distortion in the RX and audio chain and espescially
avoid clipping in the deviation limitter which will produce harmonics and distortion that add nothing to fidelity, and need to be
filtered out to prevent an overly broad occupied bandwidth.?
Unless there are new TASMA technical specifications, they are published here:?
The 15Khz channel spacing on 2m (not 440) already forces a redux of the Dev to 4.2Khz with a max 3Khz modulating frequency.
I do notice that there are pairs in 144.5-145,5Mhz that are 20Khz channel spacing but the "repeater under discussion...
147.240 (+)..." isn't there either.? The thing about "gentleman's agreements", is that just about anyone can claim exemption
and screw over everybody else.? This often gives FCC an excuse to make more rules.?
Nothing I said was untrue.? You may not understand or are offended with me or just want to jam me out.?
Maybe start another thread?
On Thu, Oct 27, 2022 at 02:42 PM, Bob Dengler wrote:
At 10/26/2022 04:17 PM, you wrote:
On Tue, Oct 25, 2022 at 09:51 PM, Bob Dengler wrote:
At 10/25/2022 01:32 PM, you wrote:
My point is, where is the energy above 3Khz comming from? Unless it is background music or road noise. The audio
spectrum from the human voice isn't there.
You must not have a tongue or teeth; my sympathies.
No - Really. There is little "need" of energy above 3khz for male voice inteligibility. It goes a little higher to 4k for women.
If you want singing or screaming of little children, you might want to go higher.
Not talking about intelligibility, but rather faithful reproduction of human speech.
The idea of getting AM broadcast to 6kc was to help music reproduction.
Yeah I remember listening to music in the 70s on cheap AM pocket radios with no high end response. For the longest time I thought Foreigner's big hit was "You're as cold as I" :)
"Bass boosting"? No one has mentioned that; what does that have to do with this discussion?
A lot of people are doing wierd things like base boosting in order to get that "Barry White" DJ sound.
Not on any repeaters around here. The XPRs I set up here probably come closest, but they are actually flat down to 35 Hz.
And there is no reason to pass the PL either.
Why not?
Added distortion of the PL tone originating at the mobile to be passed on to the transmitter?
If the user's PL distorts, a notch or 300 Hz HPF will do little to help because the harmonics will likely go up above that. At least that's what happens when I try to use my beat-up VX-7 on the repeater.
If someone really WANTS 6kc audio, it will have to be addressed throughout the chain, and keep an eye on the spectrum
analyzer.
Why? I'm sorry but this is borderline nonsense. Just what is to be "addressed throughout the chain"?
I was referring to the whole repeater chain as a system, including the user's transmitted signal to the repeater received signal and whatever processing to the
controller and whatever processing to the transmitter and whatever processing to the recovered audio at the user end. Because if you increase the modulating
frequency without either reducing the Dev or rolling off the modulating frequency, the occupied bandwidth will increase. So you will need to do whatever
adjustments "throughout the chain" to insure you don't exceed the bandwidth limited by the coordinating body by looking at a narrow enough spectrum analyzer
On 440 we don't care much about that because we have 20 kHz channel spacing, & in most cases the adjacents are either relatively unused, far away or are actually another repeater belonging to the same system.
Then I looked up K6OQK and saw 147.435 in Los Angeles. I think that one is world famous for sending the FCC packing,
and pushing the envelope well past the 7 dirty words. Maybe when Burt was involved it wasn't that way, but it became the
attractive nuisance of the amateur community.
...and what the hell does that have to do with the subject?
Southern California has a coordinating body that limits the bandwidth of 2 meter repeaters, because of a 15khz channel spacing.
Burt mentions his involvement with the 147.435 repeater that does not follow the coordinating body's bandplan recomendation for
everyone else and uses a simplex frequency in it's pair so that people who jam with high power are still able to duplex.
Not true: the 146.400/147.435 pair has always been a recognized coordinated repeater pair in SoCal for as long as I've been around anyway. There are a few others here, like 147.405/144.950 & 146.490/147.495. Basically the local community decided some 20+ years ago that the ratio of repeater pairs to simplex was a bit lower than it should be, & redefined a few pairs of former simplex channels as repeater pairs. Still plenty of simplex to go around, particularly 144.3-144.5 & 145.5-145.7. I regularly look at the VHF/UHF amateur spectrum from elevated locations in LA & rarely see more than 2 or 3 2 meter simplex frequencies in use at any one time.
Having said all that, the repeater under discussion is on 147.240 (+) the W6MEP repeater which has nothing to do with 147.435.
Bob NO6B
