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Tech808
Moderator
Username: Tech808
Post Number: 5153
Registered: 8-2002
| | Posted on Wednesday, March 09, 2005 - 10:15 am: | 
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I am moving the Posts below to this new topic, as it is more suited for replies / comments here in the Ask the Tech area.
Lon
Tech808
CEF808
N9OSN |
Chad
Intermediate Member
Username: Chad
Post Number: 188
Registered: 11-2004
| | Posted on Wednesday, March 09, 2005 - 9:08 am: |
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Yet another reason I question the "super swing" craze.
Chad |
Tech808
Moderator
Username: Tech808
Post Number: 5149
Registered: 8-2002
| | Posted on Wednesday, March 09, 2005 - 9:24 am: |
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Chad,
Nothing to question.
The Top Gun Modulator works and works well on the Magnum Radios if the person who owns / operates them is able to read and follow the Manufacturers Instructions / Advice / Suggestions.
So far I have not heard from anyone who has followed the Manufacturers Instructions / Advice / Suggestions having any problems with them.
Amps and Radios are to expensive to ignore what the man that has the radios designed and built has to say on operating them properly.
But then you will always have someone who will try it, and blow something up and then blame it on the radio or amp rather than their own ignorance for not reading and following the Instructions / Advice / Suggestions from the Manufacturer of the Radio or Amp.
Lon
Tech808
CEF808
N9OSN |
Chad
Intermediate Member
Username: Chad
Post Number: 192
Registered: 11-2004
| | Posted on Wednesday, March 09, 2005 - 10:07 am: |
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I guess my question is:
If speech has an average of a 1:4 ratio and some prefer it squeezed up for volume then what is the need of a 1:30 output ratio? Yes it makes the needle swing, but for actual voice transmission what are the advantages of modulating the carrier? If one wants to do this properly then isn't that what sideband is for? How does modulating the carrier do anything for the audio, other than inducing the great possibility for IM distortion on the receive end. The only thing I can think of is reducing the duty cycle of the finals.
Just questions I am pondering, Links to actual explanations of improvements and advantages are welcome, I think I'm missing something.
Chad |
Chad
Intermediate Member
Username: Chad
Post Number: 193
Registered: 11-2004
| | Posted on Wednesday, March 09, 2005 - 10:22 am: |
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OOps I replied again in the wrong area, sorry \doh |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 131
Registered: 2-2005
| | Posted on Wednesday, March 09, 2005 - 12:15 pm: |
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I've read that bell laboratories determined by experiment years ago that the average male voice shows about 10% modulation and the average female voice is a little less.
Swinging the carrier doesn't make any logical sense. It's a fad. It looks cool on the meter, but it actually decreases the average power output of the radio which is opposite what you want for communications. |
Chad
Intermediate Member
Username: Chad
Post Number: 196
Registered: 11-2004
| | Posted on Thursday, March 10, 2005 - 9:26 am: |
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Is that 10% processed modulation? Also keep in mind inverse square law in dealing with the mics. 10% modulation does seem like a perfect controlled instance. Keep in mind that if you half the distance to the mic you gain 6dB, so if you are at 4" and scoot the char while talking or moove a tad in to 2" then you audio level just jumped 6dB. The Human voice IS the most dynamic instrument in the world when dealing with physics, but a 4:1 compression ratio anywhere is almost unnoticable to most listeners unless the device doing the compression sucks and goes to pumpung.
Regardless, my above rambling does not support the super swing flavor of the month. |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 136
Registered: 2-2005
| | Posted on Thursday, March 10, 2005 - 6:00 pm: |
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I believe it was just measured as raw microphone output. I've never read the experiment notes, I've just seen quite a bit of reference to it in discussion of speech processing. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 281
Registered: 9-2004
| | Posted on Thursday, March 10, 2005 - 10:32 pm: |
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what do these NPC-RC mods actually do? are they just reducing carrier power and adding parts to make the needle swing more? or is the "diode-resistor" combo or adding a cap. really compressing the negative peaks of your audio?
i would love to have some legitimate facts to back me up when i tell my local "buddies" that this is not the end all be all of cb mods. here in vegas, everyone is doing it.
matt |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 143
Registered: 2-2005
| | Posted on Friday, March 11, 2005 - 6:24 pm: |
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I'd like to know too. I've never seen a website that actually showed an oscilloscope trace to prove their claims. |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 560
Registered: 7-2004
| | Posted on Saturday, March 12, 2005 - 8:54 pm: |
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the magnum delta force npc-rc mod is a bit more complicated then the mod for uniden style AM/SSB & AM only radios. that radio does show significant compression on a scope when done correctly. & with the stock delta mic it has the tell-tale 'compressed' sound. the delta is a pretty decent sounding stock radio to begin with & that mod does give it even more punchy sounding audio. adjusting the mic gain down can lighten the compression's scratchy tendencies.
as for the uniden npc-rc mod, there are more changes of parts then actual redirecting of circuitry as compared to the delta, though i've never looked at that particular radio on a scope, it too can develop the 'compressed' scratch with excessive mic gain. so i suppose it's mod has its merits, too.
as defined by the'-', kv, it is a 2 part mod combining the effects of compression with carrier reduction for the obvious amplifier setup. if you do part 3 of the mod & clip the limiter, then you can always get that bigger swing yet!
the npc-rc alone is the preferred method over clipping the limiter, just more time consuming then taking the ole diagonal cutters & ... |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 146
Registered: 2-2005
| | Posted on Sunday, March 13, 2005 - 2:49 am: |
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Okay, what does swing have to do with using an amplifier? Duty cycle? Okay. If that's important then why not just use SSB? No carrier at all means less duty cycle. Most of the radios that have this modification are capable of using full carrier AM at the same peak levels that the swing modification achieves. So it's not about signal quality or equipment duty cycle, so what is it about? It's about the signal looking cool on the meter and maybe about using an amplifier that's got a poor duty cycle. I'd just rather have full carrier AM and sound good.
This controlled carrier (swing) AM thing isn't new. It was done in the early days of amateur radio when people couldn't afford to purchase equipment that would handle the duty cycle of full carrier AM. As prices for equipment came down, this type of AM transmitter was discarded because they universally didn't sound good. The carrier is changing strength with modulation. That means it's happening at an audio rate of 3,000Hz or more. I really doubt that ANY receiver's AGC can deal with that kind of speed. So what you've got is a radio that either is overloaded or desensed. Both sound terrible. If you manage to have a signal that is capable of staying near 100% modulation on a regular basis then why bother with the swing?
I just don't get it. There is already a mode that swings like crazy - SSB. There is NO carrier transmitted, and the receivers generate their own carrier for reception. It's the logical end point of AM development. This swing thing is a just a bump in the road on the way to SSB from classic full carrier AM. One that was long ago abandoned because it didn't work well. |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 563
Registered: 7-2004
| | Posted on Sunday, March 13, 2005 - 9:12 pm: |
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which is probably why the percentage of AMers to SSBers using 10,000 watts or more is 100 to none.
ok, racer. the question from KV was what is NPC-RC, & you responded likewise. in my non-technical, boiler room schooled knowledge i explained what it does. we've already established you don't believe in the 'swing' thing, and i say it holds water. i'm not going to get into that squabble again!
full carrier & GOOD AM sound is fine, & easily obtainable for local talking with 4 watts. even 100 watts. if you want to look at AM dxers as a pack of wild animals fighting over food, so be it. the strongest survive. i cannot give you the true technical reasons why, though i have given a scenario showing how the AM 'swing' can overcome an AM carrier. i guess you can almost consider swing on AM to be a cheaters form of SSB. again, cleanliness of the signal is NOT a concern, as long as it's intelligible. using all that power to qso over 5miles is NOT how it should be done.
you don't get it-that is fine & i have no problem with that. i know plenty of people who do not get SSB, & that too should be respected. my wife WILL NOT talk or listen to me on SSB as she has no desire to tune the clarifier(actually no desire to talk on the radio at all, but that's another story). i get the SSB thing. i suppose i even operate SSB in a way that you would consider 'correct'. you could operate AM in an SSB manner, & it wouldn't be held against you. when i operate AM, i do it differently then i do SSB.
we seem here, racer to be migrating from 'swing-yes or no' to 'mode & operating practices'. the latter is what discourages cbers from getting into ham. and what made me wait nearly 30 years to do it. i monitor 6m SSB awaiting dx in this fading cycle. i know of at least 2 6m guys into AM & have been listening for them since being licensed 3 months ago-to no avail. i am not the type to be discouraged by someone who would say not to use AM on the amateur bands because it is useless, inefficient, etc. heck, i've already had longtime hams try to discourage me from using 6m at all! though a general degrading of those who use cb is what made me never take the test before. i've still heard comments(not neccessarily directed at me) that the no-code tech shouldn't be considered a real ham.
as is your right as an american to say what your last paragragh said-that is fine and agreeable. just please do not bring up legality issues regarding power, poor signal cleanliness, etc as legal is legal & your promoting (& possible use of) HF equip in any way shape or form is not legal on 11m anyway.
that said, lines in the sand erased, white flags up, howzabout those mets.............:-)or anything less inflammatory |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 155
Registered: 2-2005
| | Posted on Monday, March 14, 2005 - 7:22 am: |
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Patzerozero - You never actually said what they do. Instead you danced around the subject and said that it's more complicated in one radio than another, the audio sounds compressed, it's obvious for amplifer setup, and clipping the limiter gets you even more swing.
What does it do? Do you know of any sites that show an oscilloscope trace of the modulation waveform this modification causes?
I want to be perfectly clear - I never advised anyone to use HF equipment on 11 meters. I believe I commented saying it would be difficult to determine if someone was doing it, and that HF rigs have superior receivers, but I never told anyone to do it.
I have HF priviledges and my experience with HF rigs is on the amateur service. Don't assume that because I like HF rigs more than CBs I use them on 11 meter for anything other than receiving - because I don't. My 11 meter radioing is strictly on type accepted CBs which have as their only modification the installation of tighter filters. |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 572
Registered: 7-2004
| | Posted on Monday, March 14, 2005 - 11:06 am: |
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'that radio does show significant compression on a scope when done correctly'-
i have no website for it. i watched the mod be done & adjusted. again, in my nontecnical layman's terms, the jagged points which went up & down from nothing to 3-4" from the middle line prior to the mod were mostly 3" above & below the line during varied tones from the b & k rf generator & hitachi scope. to me it sure looked like what i was told a compressed signal is supposed to look like. but then again what do i know. i use my stock icom with the stock mic anyway. just push the compressor button 'in' for dx. that was the delta force, which i saw. never saw the grant.
your post on the cb & ham legal area/amateur hf rigs on cb sure sounds like condoning their use on 11m, whether you do it or not. |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 158
Registered: 2-2005
| | Posted on Monday, March 14, 2005 - 7:06 pm: |
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That's interesting Patzerozero. Thank you. The supposed point of the NPC modification is to compress only the negative peaks which, AGAIN, is a modification long ago used by amateurs in old tube AM gear to prevent splatter, but wasn't done in solid state.
Of course from your description it sounds as if both positive and negative peaks have been compressed so it apparently doesn't work. Thanks for the report of the failure of the modification to do what it's supposed to do.
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Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 579
Registered: 7-2004
| | Posted on Saturday, March 19, 2005 - 9:21 am: |
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then maybe it works, maybe it don't. didn't bring my tape measure to check exact differences in peaks. & never thought to draw a picture or photograph them either, as the exact measurements were less important then seeing that this particular delta force radio was working as intended. was gonna have the newly modded texas ranger 296 hooked up to the tech's scope to see how it compares to the grant xl. but seeing as it's signal has been upgraded from 'sounds really good' to 'wish my fill-in-the-blank HF radio was
that mean sounding', and i do mean SSB as well as AM, i don't see any need to waste my time. i'll just continue with my useless little cb tricks & without the aid of a power mic, go on with my life & my loud, clear, clean sounding 4 watt swinging 15 (18 SSB) cb radio & HAVE FUN on cb as opposed to what to me is nothing more then the ham-type argument of how high the dot should be over the letter 'i'. now i remember the 2nd reason it took me 30 years to get my ticket. & every time we talk on 6m SSB & are told by the oldtimers we are wasting our time there, i feel like mailing my ticket back to gettysburg & saying thanks, but no thankyou. then we start to dicuss clipping the limiters in our 5054's in their presence & it's fun all over again. |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 182
Registered: 2-2005
| | Posted on Saturday, March 19, 2005 - 2:05 pm: |
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If it had worked as intended, then it would have been obvious to you when looking at the trace. The tech also would have remarked about the difference.
The point I'm trying to make here is that it's a useless modification. If you want to give your money to your tech that's entirely up to you, but don't let him alter the designed function of your radio.
Buy a speech processor, have it installed and the limiter adjusted to 100% modulation and go about having fun playing radio.
My first rule about radio is the Golden Rule. I HATE splatter, therefore I don't splatter anyone. I don't like the sound of D104s with the amplifier turned up so loud you can hear the paint drying, so I don't use one that way. Etc, etc. |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 587
Registered: 7-2004
| | Posted on Sunday, March 20, 2005 - 12:08 am: |
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i have a yaesu desk mic for my 101e. the yo100 shows everything to be good, yet the audio from that thing is practically undecipherable. & i didn't tape the conversation, either, so i don't
remember the exact exchange at the time of the
signal being sent from the generator, or directly
spoken into the stock delta's mic.
i don't like d104's either. in fact, traded 2 of them for a brand new in the box texas ranger 296 last week. which i modded with probably every mod you dislike & have yet to get any bad audio reports. but since you can't hear me from where you are, i suppose it doesn't matter. the other 3 d104's i have have no plugs on 'em. they're waitng as trade bait. 2 are at least, i'll keep 1. for that matter, right now only my icom has any type of aftermarket mic on it, a heil icm, also have hm10-4 that sounds fine on it. NONE of my radios have power mics on 'em, though i have plenty around.
i give my tech no money. he wants his amps to sound good, so my radios should sound good 1st.
remember i said HAVE FUN', if your fun is perfection, so be it. if i can come close to performance of a $30 speech processor for half a buck, and increase my ability to talk dx on that inefficient AM mode without 40kw, that's my fun.
talk about golden rules, just as a little sidebar to my previous post, was on 50.315 AM today & had a local ham trying to talk over us on FM, SSB & CW for a good 30 minutes. i don't talk anywhere other then 6m(as that's the only capabilities i have)& as far as i've been told, he doesn't talk anywhere other then 2m, yet has a strong dislike for no-code-licensed techs. i got licensed for
this? i wonder what i wasted my time for. leave it to a ham.
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Bc910
Intermediate Member
Username: Bc910
Post Number: 474
Registered: 7-2004
| | Posted on Sunday, March 20, 2005 - 10:14 am: |
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Well as some hams like reporting ileagal opperation so much, maybe you should report him and turn the tide a bit on him! Interfering with some one elses comunications is ileagal.
BC |
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