| Author |
Message |
    
Airplane1
Member
Username: Airplane1
Post Number: 74
Registered: 5-2004
| | Posted on Friday, August 06, 2004 - 9:16 am: | 
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Hi,
Do I talk normal or make some sort of noise when setting modulation on my radio?
I tried different sounds and only get 70% unless I whistle then I can get 90%.
I have the mike gain all the way up when doing this.
I want to set it to 90%.
Thanks, Roger |
Alsworld
Advanced Member
Username: Alsworld
Post Number: 851
Registered: 1-2002
| | Posted on Friday, August 06, 2004 - 7:44 pm: |
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I am assuming you are using a modulation meter to set it. If so, you can turn up the AMC pot on the circuit board of the radio to achieve your 90%. Usually schematics an/or pitures of these on the web (depending on what radio you have) will show you which one it is.
Adjust it a little and test it with the meter. You can do this with the bottom cover off and upside down so you can have it powered on and adjust.
Be carefull and make sure you know which pot is the AMC.
Alsworld |
Tech548
Moderator
Username: Tech548
Post Number: 204
Registered: 5-2004
| | Posted on Friday, August 06, 2004 - 10:26 pm: |
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Airplane1
That's good information from AL, however, it would help to know what kind of Mic and radio you are trying to set up together. Not all radios are set up using the same procedures.
Jeff
Tech548 |
Airplane1
Member
Username: Airplane1
Post Number: 75
Registered: 5-2004
| | Posted on Saturday, August 07, 2004 - 8:30 am: |
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Hi Alsworld and Tech548,
I have a grant XL and the stock mike, I do have a modulation meter. I`m trying to set it up now to drive my KL-500 mobile amp and I`m setting the power to 2-2.5 Watts and want to set modulation too.
Thanks, Roger |
Tech548
Moderator
Username: Tech548
Post Number: 209
Registered: 5-2004
| | Posted on Sunday, August 08, 2004 - 4:34 am: |
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Airplane1
Well, in that case, I would go by with what other people tell you. Hopefully someone you trust that will give you an honest report. If they tell you that you're too loud, simply turn your Mic Gain down.
By the way, if you're a avid sidebander, that radio and amp combination will really shine.
Jeff
Tech548 |
Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 213
Registered: 6-2004
| | Posted on Sunday, August 08, 2004 - 9:08 pm: |
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Modulation meters are worthless when adjusting AMC or ALC. Modulation meters are just something to watch while you chat, they aren't test equipment and aren't accurate enough to make that adjustment. Modulation happens at an audio rate and there is no way that a mechanical meter can follow changes at that speed. Setting modulation should only be done with an audio signal generator and an oscilloscope. |
Tech808
Moderator
Username: Tech808
Post Number: 3251
Registered: 8-2002
| | Posted on Monday, August 09, 2004 - 9:39 am: |
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Airplane,
While a Modulation Meter may not be 100% Exact/Correct 99% of the people can use it to set Modulation on radio's with No Problems.
The other 1% who can afford it will use Expensive high dollar Test Equipment.
But in Real Life, Not everyone can afford or have access to 1000's of dollars in test equipment.
Or like me who has all of the Test Equipment, I still do not hook every radio up to it and use a modulation meter 98% of the time and never had anyone tell me I was Distorted or Overmodulated.
Adjust your Modulation until you see 100% on your Modulation meter then Back it down to around 75% -85% and you will be set to go.
Or like Jeff Tech548 said, ask those you are talking with if you are overmodulated. (Better than any Meter or Test Equipment).
The 1st Sargant and I Talked with you yesterday on the CEF Net and your Setup Sounded Great and you had Good Clear, Loud Audio, with NO Over Modulation.
You did a good job on getting everything setup. 
Lon
Tech808  |
Airplane1
Member
Username: Airplane1
Post Number: 80
Registered: 5-2004
| | Posted on Monday, August 09, 2004 - 11:27 am: |
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Thanks Tech808 and 1st sargant,
Thanks for the good report on the way my system sounds,
I could`nt have done it without all the great help from the members here on the forum.
I still have alot of things to do with my system so I will be asking some more questions, Hope everyone dont get sick of me.
Looking forward to talking to you and 1st sargant on CEFs again soon.
Roger |
Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 217
Registered: 6-2004
| | Posted on Monday, August 09, 2004 - 12:46 pm: |
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Overmodulation does not cause distortion unless it's VERY overmodulated. Modulation meters are simply fun to watch, they are not test equipment. Adjusting modulation is not possible to do accurately unless you are watching the waveform on an oscilloscope.
Even small amounts of overmodulation result in additional sidebands being generated on adjacent frequencies. That is what bleedover actually is. It's not detectable on the channel you're using until there is so much overmodulation the detail of the your voice suffers.
If you want to adjust your modulation without an oscilloscope there is a way to do it and make sure you aren't causing bleedover.
Get a friend to act as your assistant. The better his radio is with adjacent channel rejection, the easier his job will be. Choose 2 adjacent channels that are pretty quiet - no skip or backround noise. The channels need to be right next to each other - no "A" channel gaps. Your assistant should have a good copy on you when chatting on the same channel. He should adjust his RF gain control so you are mid scale at the most on his S-meter. Your signal shouldn't be so strong that he'll think you're bleeding over when it's just a strong signal making his receiver misbehave. When this has been accomplished you should change to the adjacent channel, make a small modulation adjustment, and then talk loudly or whistle for a few seconds. Then change back to the channel he's listening on to see if he heard any bleedover. What he's listening for is just scratchy noise on the frequency that only happens when you're talking - bleedover. It should happen the entire time you're talking, not just when you first start talking. There is a brief period of time that the limiter circut takes to work and "limit" the signal. If he didn't hear any bleedover then you should repeat the proceedure until he does. Once he hears bleedover you should back down the adjustment slightly until he doesn't hear it anymore. When he stops hearing bleedover you are as close to 100% modulation as you can be without an oscilloscope and tone generator. You're also sure that you aren't causing bleedover.
Still, the only accurate way to adjust modulation is with a tone generator and an oscilloscope so you can watch the waveform, but with the above method at least you know that you're not causing any bleedover.
Good luck! |
Airplane1
Intermediate Member
Username: Airplane1
Post Number: 123
Registered: 5-2004
| | Posted on Wednesday, September 08, 2004 - 8:29 am: |
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Hi, One more question, What does the mic gain do exactly?
Does it control modulation?
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Cuddlebear
Intermediate Member
Username: Cuddlebear
Post Number: 262
Registered: 3-2002
| | Posted on Thursday, September 09, 2004 - 3:48 am: |
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Yes, That's it's function. |
Gravedigger162
New member
Username: Gravedigger162
Post Number: 8
Registered: 8-2004
| | Posted on Thursday, September 09, 2004 - 7:04 pm: |
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What is the CEF net and how and when do you all talk on it. And what do you have to do, or requiered (not shure on spelling) to do/have to join? |
Tech808
Moderator
Username: Tech808
Post Number: 3529
Registered: 8-2002
| | Posted on Friday, September 10, 2004 - 8:20 am: |
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Gravedigger162,
CEF Net, INFORMATION!
(Copper Electronic's Forum) Net.
The "OFFICIAL" Home / Stand By Channel for CEF MEMBERS will be Channel: #13 / 27.115 "LSB" (Lower Side Band).
This Net will be held Every SUNDAY at:
12pm ~ Eastern Time Zone
11am ~ Central Time Zone
10am ~ Mountain Time Zone
9am ~ Pacific Time Zone
The CEF NET (CB) FREQUENCY, will be Channel 13 / 27.115 LSB (Lower Side Band.)
NOTE!
We have also started a CEF "10 Meter" (HAM) net starting 1 hour after the start of the Regular CEF Net on 28.360 "USB" (Upper Side Band)
 NOTE!
To Participate in the 10 Meter Net's you MUST be a Tech Plus or Above FCC Licensed Ham Operator.
CEF 10 Meter Net Controller's are:
EAST COAST Net Control: / CEF #132 - 10M# - 2 / Bruce ~ WA4GCH
MID-WEST Net Control: / - 10M# - 14 / ~ Moderator558
WEST COAST Net Control: / CEF #833 - 10M# - 1 / Tech833 ~ KG6AOH
CEF Net Controller's for the REGULAR CB CEF NET's.
MIDWEST " Net Control: TECH808 ~ CEF #808 "
EAST COAST " Net Control: IRONMASK ~ CEF #100 "
WEST COAST " Net Control: ALSWORLD ~ CEF #101 "
All of those wishing to participate in the CEF NET, will be issued a CEF Call Sign / Number.
These Call Signs / Numbers will be issued on a first come / first served basis.
By having, EAST COAST / CENTRAL / and WEST COAST Net Controller's, we should be able to cover the entire U.S. if condition's are good.
If the condition's are not good this will allow to to still have a chance to check into the NET for your Area.
We have also developed a Special Area for the CEF Net Member's. "CEF NET CONNECTION'S" Here in the Forum for CEF Net Member's.
To apply for your: CEF NET Call Sign / Number, PLEASE e-mail me direct at: Tech808@copperelectronics.com
PLEASE include the following information when applying for your CEF Number."
#1 ~ Your Full Name
#2 ~ Your Copper Fourm Name / Handle
#3 ~ Your City & State
#4 ~ Your Correct e-mail address
#5 ~ Your CEF Call Sign / Number will be e-mailed back to you.
NOTE!
If you are also applying for a CEF 10 METER # please include your Ham Call Sign, Issue Date and Experation date.
NOTICE!
We have also added the CHAT ROOM which is OPEN for the CEF Member's and other's to use during the Net's.
You will find a LINK to the CHAT ROOM to the left of this post Under the CEF Net Area right under Membership List.
SEND ME YOUR INFORMATON REQUESTED ABOVE AND COME JOIN US ON THE SUNDAY CEF NET's AND HAVE SOME FUN! 
NOTICE!!!!!!!!!!
 ADDITIONAL AM NET ADDED!
WE HAVE NOW ADDED THE CEF AM NETS THAT STARTS EVERY SUNDAY 1 HOUR BEFORE THE REGULAR CEF SSB NET ON CHANNEL 13 / 27.115!
THE CEF AM NET CONTROLERS ARE:
EAST COAST NET CONTROL (POSITION OPEN)
MID-WEST NET CONTROL CEF115 / GATOR
WEST COAST NET CONTROL CEF833 / Tech833
Lon / CEF808
Tech808
Tech808@copperelectronics.com
|
Gravedigger162
Junior Member
Username: Gravedigger162
Post Number: 11
Registered: 8-2004
| | Posted on Friday, September 10, 2004 - 11:11 pm: |
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How do I get a CEF #? I usually Go by 162 On SSB!
And I live in North East Kansas! I run a Cobra 142 GTL So I do not have a Freq. Counter. I will be there 11am Central time Sunday! |
Tech808
Moderator
Username: Tech808
Post Number: 3543
Registered: 8-2002
| | Posted on Friday, September 10, 2004 - 11:36 pm: |
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Gravedigger162,
To apply for your: CEF NET Call Sign / Number, PLEASE e-mail me direct at: Tech808@copperelectronics.com
PLEASE include the following information when applying for your CEF Number."
#1 ~ Your Full Name
#2 ~ Your Copper Forum Name / Handle
#3 ~ Your City & State
#4 ~ Your Correct e-mail address
#5 ~ Your CEF Call Sign / Number will be e-mailed back to you.
Lon
Tech808
Tech808@copperelectronics.com |
