| Author |
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mikefromms
| | Posted on Tuesday, October 07, 2003 - 6:45 pm: | 
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How much ssb power do you guys use to drive the KLV 250 or 350? Do any of you control it by turning the powermike way down to lower modulation? What's the best method? I understand AM is best at about 1 watt. What about SSB?
mikefromms |
Highlander
| | Posted on Tuesday, October 07, 2003 - 9:04 pm: |
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I run about 10 pep into mine. What radio are you using? For my Roadpro I adjusted the ALC pot in the radio down to do 10 watts max. On my Galaxy 2517, I turn the RF power knob on the radio all the way down, this yeilds about 15-18 pep. For my Lincoln, I switch the mic gain button to low, this reduces my pep on that radio to around 15 16 watts pep. (The variable power on the Lincoln does not affect SSB power). I know other lincoln owners that turned their ALC down, instead of using the mic gain. I think it works fine either way, just a matter of preference. The way I've always understood it, mic gain IS variable power control when you are using SSB phone. I remember a post about this a couple of years ago on Panther's old board, but can't remember the outcome of that discussion. |
ss8541
| | Posted on Tuesday, October 07, 2003 - 11:50 pm: |
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hey highlander, been a while since i talked to you. i remember the outcome of that post...if it is the same one i am thinking about.
in any event, there is such a thing as 100% ssb modulation. you must be using a scope and a 2 tone audio generator to see this( there will be no crossover points at less than 100% modulation). by using the mic gain control to limit power, you will not be hitting 100% ssb modulation. you need to adjust the alc to limit power and stay at 100% ssb modulation. there is not a huge on air difference, but there is a difference.
as for the amps mentioned here, the power inputs you mentioned is a safe input.
i do like that the pre-amp uses a band pass filter to keep out of band signals from being amplified(schem shows this). the newer versions even have protective diodes to keep the pre-amp from being blown from high inputs. they are on the output also to protect the radio. i have not swept the pre-amps of these with a tracking generator yet to see the gain or bandwidth of the pre-amp. i may do it with this one and let you know. i know you get into this technical wise highlander, so this may be beneficial to you.
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mikefromms
| | Posted on Wednesday, October 08, 2003 - 11:09 am: |
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I never use the mic gain button my my Lincoln. Didn't think it really made any difference. I was referring to the powermike, a D-104 hand held, when I asked the question. So 10 watts is recommended? I did adjust down to that range 10 to 15 yesterday. The amp on low hits around 100 on high notes, whistles. It seems to average around 50 to 80 when talking normal. Is that about what you guys get on low?
mikefromms |
mikefromms
| | Posted on Wednesday, October 08, 2003 - 11:11 am: |
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Oh, I'm using a President Lincoln. Working on TVI right now. Got a filter ordered and trying to tune down somewhat. Will look into more grounding later.
mikefromms |
Highlander
| | Posted on Wednesday, October 08, 2003 - 4:56 pm: |
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Your output sounds right to me, it's doing it's thing.
Hey Richard, hows it going? Yeah, I remember now....I'm too lazy to search for it. In any case, the mic gain button seems to work ok for me. I do that for my klv mod351p in the truck when I run power. I want an O' scope! Can you recommend a nice entry-level(cheap) one that would be good for learning some basics, setting modulation, etc? Also, I am thinking about getting my lincoln chipswitched, 12 metered, and maybe SP1A installed, and wanted your thoughts on if doing shottky barrier diodes and a channel guard would be worth it as well? |
ss8541
| | Posted on Wednesday, October 08, 2003 - 9:41 pm: |
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mike, the 250 works best in am mode with around 2w of input carrier and 10w of swing. with the amp in high, this will give you about a 50w carrier and 200-250 watts of swing. for ssb, an input of 10wpep is plenty.
for the money, the klv can't be beat. but, you really do not want to drive these hard. they are not designed to handle this at all. if you do drive it hard, you will be replacing the 4 mosfets on a regular basis, and could possibly destroy the power supply.
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highlander, the tenma line would make a good entry level scope. they are cheap but work well. you could probably find one cheap for sale on ebay. i know you can find used scopes at ham fest(any brand). there is always someone selling used test equipment at those all the time.
it doesn't have to be calibrated or measure voltages precisely, it just needs to work properly for what you want to do with it. you need a bandwidth of 50mhz for the 10-11mtr bands. if you find one at a ham fest, tell them to turn it on and give you a primer on how to use it. this will 1, let someone who already knows how to use one give you quick lesson(you'll learn more on your own after you play with it a while) and 2, give you a chance to make sure it works b4 you walk off with it.
the cg is a nice addition for increasing selectivity, but as you know if someone is running a splatter box, it will do nothing. i have tried the schottky diodes several times in the past and could tell little to no difference in rx sensitivity. so i don't do those any longer. replacing the rx rf amp with a 2sc2999 makes more of a difference than the diodes. and the rx rf amp upgrade works in all modes where the diode replacement only works for am.
i also got to sweep the pre-amp of a klv250 today. the gain from the factory was 12.3db with a -3db bandwidth of 2.3mhz. the center freq was around 27.250mhz and the 3db edges were at 26.100 and 28.400. after some tuning the gain rose to 14.4db but the -3db bandwidth shrunk to 1.9mhz with the -3db bandwidth at 26.150 and 28.200. i shifted midpoint of the bandwidth to 27.200mhz(ch20). |
Bruce
| | Posted on Thursday, October 09, 2003 - 12:41 pm: |
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SS8541
Interesting comment on diodes i bought 100 of them ( a lifetime supply ) and found prety much as you did no real change. Where did you find the 2SC2999's ?????? i had to settle for net23 or what ever was out there ....and agreed they did work after i use the 3rd one ..... QC on " replacement" transistors is lacking. Installing the channel guard if you want to use one should be done just before the 10.695 exsising filter and not inbetween the 10 mhz bandpass filter which will interfere with the NB. Interesting gain/bandwidth comments never even thought to check one the few ive fixed were blasted by to much input and easly repaired.
bruce |
mikefromms
| | Posted on Thursday, October 09, 2003 - 5:33 pm: |
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I think I smoked those diodes you were talking about earlier. KLV 250 out of service.
mikefromms |
mikefromms
| | Posted on Thursday, October 09, 2003 - 6:17 pm: |
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Copper has handled this problem without my asking.
Thanks Coppers!
mikefromms |
Alsworld
| | Posted on Thursday, October 09, 2003 - 8:39 pm: |
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Mike,
great to hear of the great customer service.
TVI is a tough battle for sure, but with my Lincoln/D104 setup, I created a lot myself by just overmodulating. Keep that D104 at no more than "4" without the amp, and either a "2" or punch the mic gain button on when using your amp. Made quite a bit of difference with my TVI problem. Hope that helps.
Alsworld |
mikefromms
| | Posted on Friday, October 10, 2003 - 6:22 pm: |
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Alsworld,
Some of the guys around here like to hear you "nasty loud." But my TV can't stand much of it. Slowly, I'm getting 10-8 around these parts.
Got a TVI filter from Copper today but haven't hooked it up. Be glad when my full setup is 10-8 again. Got to get something in the mail to Coppers.
mikefromms |
ss8541
| | Posted on Friday, October 10, 2003 - 9:31 pm: |
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hey bruce,
yeah, the nte/ecg23 is a no go. it works but it has broke into osciallations too many times on me in the past. i would have to add some capacitiance to stop the osciallations. i even had them work fine for me, but oscillate once the owner put it on an actual antenna. i will not say here where i got the 2999's. that company also distributes cb equipment(and will sale to the public) so they are a competitor to copper, and i don't want it to look like i am sending business somewhere else.
mike,
copper is good about things like this. this is one of the reasons i post here. there was once a company in the deep south that had the largest cb forum at at the time. i never posted once there because of how that company ran things(i don't think they would have let me if i tried). that company is gone, but copper is still around. |
Bruce
| | Posted on Friday, October 10, 2003 - 10:32 pm: |
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SS8541 you got that right on several ecg23 squeeled like a pig on several 2950's i tried it on it took 3 of them before i got one to work on the lincoln. But when i got a good one WOW ! if i had more time i have several more brain storm's for that lincoln including a 4 pole CG ( 2 back to back on one board ) but right now tring to come up with a true 40-10 dypole has become a challenge.
Well one good thing i have enough diodes to last untill im too old to worry ... and bought the entire 100 for $4.50 rad-shack wanted at the time $2.99 for 4......i just tossed them in with the other 50 lbs of small parts .... that one day i will be happy to have!
Bruce |
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