Are you in the market for a clean original owner 2547 with only extra channels and no power mods?I am in the market for a new base station and am considering a Galaxy-2547 because it fits my budget and has very good reviews. I currently own a Galaxy DX-959 and I know that the innards of the 2547 and 959 are the same but the 2547 has better ergonomics for me.When looking at various websites that sell the 959 those sites claim 30 watts of "swing" after being "specially tuned". I also saw a Lincoln 2 which was rated by the factory at 28 watts but with a "special tune" are claimed to put out close to 50 watts. Really?Is it possible that those radios could put out that much power PEP with a "special" tune?
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Maximum Swing Power?
- Thread starter wa373
- Start date
Yes. A diode detector like most people have will not handle high percentages of modulation. A synchronous detector or sdr in sync mode will handle 300% just fine....as long as it's clean. Trash is trash.
None that I know of. I honestly wouldn't see the point. I have yet to hear a _clean_ signal on air with a modulation percentage higher than what a standard diode detector can handle. Most detectors, that I've seen, start distorting between 105% to 125%. Most (damn near all) of the, "big swinging," radios that I've heard on air, or seen in operation, aren't clean. They're either flat-topping on the positive peaks, pinching off the negative peaks, or some combination of both, to get that really high ratio, despite it being pretty useless due to all of the distortion and harmonics. At that point, the type of detector you have is irrelevant, because you can't detect a clean signal when it was transmitted in such a nasty fashion. Clean, high ratio, transmitters are out there, but it's not often that I hear one.
I have a S45HP with the "Top Gun" modulator and it will bust the crap out of a signal that is all carrier. Dead key set for 2 watts and swinging to 80 watts and no amp got heard on the "Pooper Bowl." I just called in and asked "Why are you little mud duckies on my channel?" The chaos that ensued was a hoot to listen to.
Not a fan of that top gun modulator. In stock form mine was "loud" and it made the meter bounce around a bunch, but it got out, and sounded, much better with it removed.
Back on topic... What's the point of a 40:1 ratio though? If a radio is capable of 80W PEP on AM, then it should be capable of doing that 80W PEP with a 20W carrier, a 4:1. If you want super punchy and extra loud audio, you could go to a 5:1, so a 16W carrier, or somewhere in between, as long as you don't pinch or clip. You'll sound great on any receiver, not just the ones that can handle high radios, and the AGC won't be pumping, on the receiving end, on pauses either. I'd bet that everything else being identical, that radio with a clean 4:1 would out talk the way it sits now. While your PEP might hit 80W, you're average is significantly less. This also causes the signal to fade out more in step with the distance away from you. I hear this all the time when I'm in the truck; blowing my ears out as they pass, then they just get progressively quieter. A normal ratio remains almost the same volume right up until the edges of their range.
Going the other way, less than 4:1, is even worse, I think. You're taking power out of the sidebands, which is where your audio is, and you'll sound quieter in comparison. You might be able to wipe people out with just your dead key, and bust through that way, but that's not for me.
I try to copy what the broadcast stations do, just on a much, much, smaller and cheaper scale. This hasn't failed me yet.
I just bought it as it is. I did no tuning or adjustments to it. Every time I use it I get a lot of people wanting to buy it. I guess it just sounds good to their ears. I talked SSB to Washington State from my son's drive way in Austin, TX and he was blown away.
He told me he was going to steal it so I took it out of the truck and put it in my locking brief case.
According to Captain Kilowatt commercial stations use asymmetrical modulation going as high as 150% modulation.
He told me he was going to steal it so I took it out of the truck and put it in my locking brief case.
According to Captain Kilowatt commercial stations use asymmetrical modulation going as high as 150% modulation.
Ahem........that's 125% not 150% for positive peaks. The negative peaks however MUST be maintained at no more than 100% and a proposal has beenmade to limit them to 96% to allow for an extra margin of error to prevent splatter. I don't thinkthat is necessary however as long as the proper monitoring equipment is used and the person doing the testing is competent. That last part however seems to be where the weak point is. Too may stations today simply employ an IT guy with zero RF experiance.
Sorry did not mean to misquote you. It must have been CB myth creeping in there.
But the IT guy has the word "Engineer" on his resume!
That usually just means he played with toy trains as a kid.
If I've done my math correctly, it happens sometimes, the 125% that commercial stations use for speech broadcasts is just a curly blonde one over a 5:1 (123.6%, I think) ratio. As Captain Kilowatt pointed out though, the negative peaks must not be allowed to pinch off. The positive ones shouldn't be allowed to flat-top either.
As for the S45HP in particular, it has two tricks up it's sleeve to get the meter swinging. The first being the, "Top Gun Modulator," board. It replaces the DC link, normally a 5.6k resistor (R412 in my Deltaforce / R238 on an EPT3600 RCI chassis), between the high power adjustment POT and the regulator input. It also taps into a couple other points as well, but it seems like it is supposed to positively offset the carrier power in step with the audio to give extra "swing." While it did make my, continuous reading, meter swing when modulating, it also distorted my audio envelope in a way that I didn't like the look or sound of. Also of note, the Top Gun Modulator is only active in AM mode and it can't be turned off. It has no effect at all in SSB.
The second trick it has is some sort of soft clipping/gain tweaking board. It only has 2 wires and sits between pins 1 & 2 of the mic preamp IC. That is normally just a 270k resistor (R279 in my Deltaforce/R165 on an EPT3600 rig) that provides the negative feedback for the op-amp. I'm not 100% sure what was under the black epoxy on the tiny board, but it looked like 5 SOT23 packages and maybe a couple SMD resistors or something. I'm guessing they were either diodes, diode connected transistors, or diode connected JFETs, I wasn't bothered enough to try to get the epoxy off, it just went in the junk box somewhere. This little thing might have worked well, except that the mic amp's output amplitude increases as you turn the power control up. This caused the effect of this little board to be much different at full power as opposed to low power. This board is active in all modes of operation, although to be honest, I didn't check what it looked like in SSB. It might have been alright there, but I was purely an AM guy in those days. In my opinion, I like the sound of a small amount of soft audio clipping/tube emulation. I think it makes your audio pop out from the background, especially if it's combined with a ratio a little over 4:1. It has to be clean to reap the benefits though, and fresh out of the shrink wrap, my S45HP wasn't at all. Maybe mine was a flop, I only have how it was to go by. It was a decent rig while I had it though. I still have my first gen Deltaforce. I'll never get rid of that thing.
As for the S45HP in particular, it has two tricks up it's sleeve to get the meter swinging. The first being the, "Top Gun Modulator," board. It replaces the DC link, normally a 5.6k resistor (R412 in my Deltaforce / R238 on an EPT3600 RCI chassis), between the high power adjustment POT and the regulator input. It also taps into a couple other points as well, but it seems like it is supposed to positively offset the carrier power in step with the audio to give extra "swing." While it did make my, continuous reading, meter swing when modulating, it also distorted my audio envelope in a way that I didn't like the look or sound of. Also of note, the Top Gun Modulator is only active in AM mode and it can't be turned off. It has no effect at all in SSB.
The second trick it has is some sort of soft clipping/gain tweaking board. It only has 2 wires and sits between pins 1 & 2 of the mic preamp IC. That is normally just a 270k resistor (R279 in my Deltaforce/R165 on an EPT3600 rig) that provides the negative feedback for the op-amp. I'm not 100% sure what was under the black epoxy on the tiny board, but it looked like 5 SOT23 packages and maybe a couple SMD resistors or something. I'm guessing they were either diodes, diode connected transistors, or diode connected JFETs, I wasn't bothered enough to try to get the epoxy off, it just went in the junk box somewhere. This little thing might have worked well, except that the mic amp's output amplitude increases as you turn the power control up. This caused the effect of this little board to be much different at full power as opposed to low power. This board is active in all modes of operation, although to be honest, I didn't check what it looked like in SSB. It might have been alright there, but I was purely an AM guy in those days. In my opinion, I like the sound of a small amount of soft audio clipping/tube emulation. I think it makes your audio pop out from the background, especially if it's combined with a ratio a little over 4:1. It has to be clean to reap the benefits though, and fresh out of the shrink wrap, my S45HP wasn't at all. Maybe mine was a flop, I only have how it was to go by. It was a decent rig while I had it though. I still have my first gen Deltaforce. I'll never get rid of that thing.
