Uh...200 watts FM.
Nice video!
You nailed it, good job! Beginner luck possibly.
Nice video!
You nailed it, good job! Beginner luck possibly.
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Modulation meter low bars on radio
- Thread starter Limeybastard
- Start date
That's some serious current draw previously. You can see how much current draw was wasted to just get about 20% more wattage.
Some people are watt-heads and will squeeze every available watt out of a radio or amp. The truth was, is, and always will be that it takes multiplying the power by 4x to get just 1 extra signal strength on the other end. You would now have to increase your power to 1600 watts to get there then up to 6400 watts to get another one. The first major amplification stage is always the most crucial.
Excessive PEP power leads to shortened final life and excessive heat. Excessive deadkey power is wasteful too. This is only useful for those key-down competitions which are meaningless to me. It's similar to turning up the high idle on your car which will waste fuel, create more heat, and serve no purpose to overall performance. Too little deadkey isn't good because the excessive swing will cause audio distortion.
You have a powerful radio and with an ideal antenna system, you will have an excellent station.
Maybe other people reading this thread can learn something from it.
Thanks for the kind explanation, makes sense. Im all for efficiency.
One thing though, wouldn't a high dead key also act as a not sure howmto word this, someone spreading the sea for the cavalry to speed through with little to no resistance?
My pleasure! Someone helped me with it years ago on doing this same thing, now I just paid him back!
Yes, interesting analogy.
One observation, when I was adjusting low power dead key ( mic gain was down ) with RF Power all the way turned to bare min on the knob. I noticed the wattmeter needle would for example register at 10W but when I released the mic key the meter momentarily jumped to around 15W. Only did this behaviour when I was adjusting the low power VR19 .
Thanks for the meter tip, I increased it a little so no it looks "better" with more movement. I just used the meter pot to make the display show more bars whilst modulating.
Also another observation, the side of the radio was getting hotter than the actual amp section (could feel it since cover was off), with side I am refering to the side where the board is, the area where those finals are attached to the chasis of the case, suprisingly the frame feels hotter here than the amp.
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I think the next adjustment is going to lower the SSB output, during Auudiooo test, the meter shows its hitting 500W with about a peak of 59A. Shall I leave this side of it ?
Mark the SSB pot with a marker first for reference, then bring it down to a strong 400 on peaks.
I dont have the radio open in front of me, but I recall last night that there was two SSB pots in there or so.
Also, do I do the adjusting with mic gain fully turned clockwise I assume.?
A question goes begging, why would the radio leave the factory with these pots so far off? At the end of the day, wont this cause aggrevation for the customer since its bound to burn up during the warranty period and thus the USA agent must spend money to repair them?
There is only one pot labeled SSB power. Don't touch the other one.
Mic gain should be up to where you would normally run it. SSB has no carrier so you do need good modulation to check and set it.
I never had to adjust SSB power because it was usually within spec's. Yours at 500 watts is high.
Why yours would be so high would reflect on lack of Q-control letting them pass by like that. Shame!
Mic gain should be up to where you would normally run it. SSB has no carrier so you do need good modulation to check and set it.
I never had to adjust SSB power because it was usually within spec's. Yours at 500 watts is high.
Why yours would be so high would reflect on lack of Q-control letting them pass by like that. Shame!
These newer versions of the 2970's sparked my interest so I just ordered one from Bell's CB shop. I went with the N2 version which is just the 200w mosfet version of yours. I'll be curious to see what it does out of the box. I 'm not having any of those so-called peak and tune mods just a new factory sealed box.
That brings up a question, did you have your radio peaked and tuned at time of sale or was it factory fresh?
That brings up a question, did you have your radio peaked and tuned at time of sale or was it factory fresh?
Yeah, if you look at the mainboard on my
No Sir, i didn't have a peak and tuned. This service wasn't even offered since my seller just sells these items and doesn't offer those options.
Congratulations, hopefully you'll enjoy yours well. Was going to give you advise about checking things over before going full throttle hahaha. Never mind...
Glad to hear you didn't do any peak and tune mods.
I will post my findings on the N2 version by the end of the week.
I will post my findings on the N2 version by the end of the week.
I tried adjusting VR14 SSB Power, apart from going up , I couldnt really get it to go down further, was attempting to hit no more than 400W with loud modulation audioooo test, still hits almost 500W. ( with RF Power dial turned full clockwise ).
An another note, Now I know why you told me to adjust Modulation V17 before doing the High and Low dead key adjustments. I turned VR17 higher and AM started to hit 500W PEP also. , luckily was marked POT and put it what it was. VR17 turned a lot to max by the way, so currently eyeballing it , the VR17 is past miday, almost 75% set . I know it doesnt mean much, but it definately wasnt or is 90% turned, then again meaningless without measurements I guess..
An another note, Now I know why you told me to adjust Modulation V17 before doing the High and Low dead key adjustments. I turned VR17 higher and AM started to hit 500W PEP also. , luckily was marked POT and put it what it was. VR17 turned a lot to max by the way, so currently eyeballing it , the VR17 is past miday, almost 75% set . I know it doesnt mean much, but it definately wasnt or is 90% turned, then again meaningless without measurements I guess..
Cut the RF power knob back some when you're on SSB and you'll be fine.
Modulation drives the PEP especially on AM so that adjustment will have an affect on your peak power. 75% up is fine. I've had radio's NIB that had the AMC pot nearly all the way down.
I'll have my N2 radio by Saturday.
Modulation drives the PEP especially on AM so that adjustment will have an affect on your peak power. 75% up is fine. I've had radio's NIB that had the AMC pot nearly all the way down.
I'll have my N2 radio by Saturday.
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