Well I know Jazz has not had time to reply.......but I guess from all the PM's and positive pm's I have gotten all I can say is THANK YOU............. Nuff said. maybe they do stuff different in the UK. Any way thanks and take care.
Glad to hear you've had so many pm's of support,pity they ain't got the gonads to do it on an open forum, but I'm sure it makes you feel justified in your claims, but then Antron / Solarcon sell many many Antron A99's and those people think they are good antennas, so delusion is rife in cb world.
Nuff said, I don't think so !!!
You claim 1w swinging 8 - 14 which is between double and 3.5 times the Carrier / P.E.P 4:1 ratio that gives 100% modulation (the perfect modulation for a clean AM signal). Your suggesting a chronically overmodulated signal full of harmonics being amplified by a non linear amplifier is a good idea, it has little if any filtering too by the way.
For a 1w input ideal P.E.P would be 4w P.E.P
I suggest 2w Carrier swinging to 8w P.E.P a perfect input for that amp and you tell me I'm wrong, I bet you a spectrum analyser won't tell me I'm wrong.
You suggest we do it differently in the UK, I do anyway, I can't speak for everyone as Ancient Modulation is barely if ever used here on CB, but I started on a President AR7 back in 78, you may know it, it's a FCC certified radio, and a damn good one at that, my next radio was a 120 Ch Cobra 148 GTL DX,pb010ab followed days later by an export version Stalker 1X, you will probably have seen that in the states too, in 40 AM/SSB guise, we got 80 AM/FM/SSB.
So right away I've started on 3 first class radios, all with AM, All Uniden made, which we used regular up till nov 2nd 1981 when our Govt in its infinite wisdom decided to legalise 27.60125 - 27.99125, on FM or more accurately Phase Modulation.
I also used the 148 on UKFM as it slides easily to the -3.75 Khz offset our government chose as well as still using it on AM for a couple more years and SSB till I got busted with it in 83, basically I was a daft kid of 16 and was overdriving the amplifier with it and causing allsorts of interference, which brought the wolf to the door and me seeking how to prevent it happening again.
I've had many radios since, all export Uniden or Ranger clone Sideband radios with AM. With an unmeasureable amount of Amplifiers, too many for my memory to recall.
you also claim the same P.E.P figures for SSB.
30 years later, almost 31 and your trying to convince me 1w carrier/dead key, call it what you want. swinging 8-14w P.E.P is a better setup than a 2w carrier swinging 8w P.E.P signal
Its no secret 100% modulation is the cleanest and best signal to amplify for a clean output and its a well known fact a 4:1 carrier ratio to P.E.P is whats required to achieve that without distortion/harmonics. I'm sure by now Freecell would have a sore neck from nodding, cause despite his people handling he was a very smart guy. I'm sure a few others will be too and those that don't agree about what I'm about to type, don't pm me bullshit, say it out here in the open, I don't bite, much.
Now we'll get to the crunch, and do some figures:
Positive Modulation % = SQ RT of P.E.P - SQ RT of CARRIER in Watts / SQ RT OF CARRIER in Watts X 100 :
Lets start with an easy one 4w P.E.P and 1W Carrier
4W P.E.P (sq rt is 2w) 2w - 1w (1w is sq rt of 1w carrier) = 1W / 1W = 1X 100 = 100% MODULATION, simples.
now we'll do it my way and both your minimum and extreme, I'll round up to keep it tidy
my 8W P.E.P and 2w carrier = sq rt 8w P.E.P = 2.82w - sq rt of 2w = 1.41 = 1.41w/ 1.41w = 1 x 100 = 100% modulation.
lets try your best case scenario, cause your worst is frightening,
8w P.E.P and 1w Carrier already established both of these sq rt's in above 2 examples so i'll leave all that out:
2.82w - 1w = 1.82w/1w = 1.82 x 100 or 182% modulation, that's your best case scenario going through an amp with no filtering of any significance.
now the worst case, dearie me: that would be 14w P.E.P and 1w carrier, in your words not mine:
SQ RT of 14w P.E.P = 3.74w now we know SQ RT of 1 is 1 so here goes :
3.74w - 1w = 2.74w/1w carrier = 2.74 x 100 = 274% modulation going through an amp that ain't the cleanest to start with.
now we come to SSB, according to manufacturer, is fitted with a 12 amp fuse, so its safe to say with headroom draws about 10 amp at full belt, 13.8v at 10 amp gives a dc input of 138w, allowing for an optimistic 70% efficiency (thats where your heat goes) your looking at 138 x 70% = 96.6w, even if it was 100% efficient, which it ain't or it wouldn't heat up your looking at 138w P.E.P maximum.
I reckon this amp has about 10db gain with those 4 transistors biased the way they are., so when your pals are hitting 20w input the amp can't sustain 200w output and fries.
your friend/s with 3w swinging 20w are actually putting less overmodulation / distortion through than you are, whats blowing their amps is too much drive, yours ain't blown yet but it will be spewing shite all over the place and soon will blow at that level of abuse, thats if you don't get a knock at the door from the FCC first for causing mayhem all over the spectrum.
your friend/s overmodulation level is 20w P.E.P and 3W carrier,
sq rt of 20w P.E.P is 4.47, sq rt of 3w carrier is 1.73w so
4.47w - 1.73w = 2.74w / 1.73w = 1.58 x 100 = 158% overmodulation, another splatter box.
Feel free to get your pm buddies to check my figures, and bare this in mind, no matter what power meter you use be it bird,lp100,dosy or any other, it can't differentiate power on the fundamental frequency to power outside it. Only tool that will do that is a spectrum analyser which will break up exactly where that power is going. I can tell you this much without looking at a spectrum analyser at 182% modulation and over it ain't all going on the fundamental frequency.
now I've had time to answer you:
NUFF SAID !!!!
P.S. we don't have that problem using FM/PM as its not amplitude modulated, but don't mean some of us don't know AM swing is bullshit and when amplified, filthy.
73 Jazz
