| Author |
Message |
    
Cobra0020
| | Posted on Thursday, July 31, 2003 - 12:04 am: | 
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I have A 2990 that does 300 watts on am. I want to turn it down alot, What would i need to touch to turn it down..
Thanks,
Cobra |
Allagator
| | Posted on Thursday, July 31, 2003 - 12:26 am: |
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Cobra0020 i dont think the 2990 will do that many watts !!!! So i would start with your power meter !!! use another meater and see what it does ???????? and get back to me !!!
Allagator |
RCI 2990
| | Posted on Thursday, July 31, 2003 - 12:43 am: |
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300 watts???? NO WAY DUDE! My 2990 i had did about 175 to 195 on AM and about 225 on SSB with the power all the way open.. And this was after i had a PPC mod done to it. I belive it is the meter to blame.. |
Taz
| | Posted on Thursday, July 31, 2003 - 1:15 am: |
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sure, and I bet it was worked on by the famous Tyler. |
Bullet
| | Posted on Thursday, July 31, 2003 - 3:55 am: |
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ya bad meter dude!
that radio is not capable of that, those are a pair of 80 watt rated finals.(2290's)
find a good meter and recheck it!
if its been peaked it should do "around" 150 peak watts.
carefull though as these radio's are known for power supply failure. dont run the heck out of it without beefing up that weak link.........
i have known several guy's with these and the turbo and the one's without the modified power supplys always fail sooner or later the ones that have it done are still on the air........
if you live close to louisville Ky go see nomad!!! |
Cobra0020
| | Posted on Thursday, July 31, 2003 - 6:39 am: |
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no man I checked on Three different meters. Is there any way they may have changed the pills out. that is my only guess |
ChillyDog
| | Posted on Thursday, July 31, 2003 - 9:28 am: |
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Cobra0020,
Make sure that when you are checking power you are transmitting into a dummy load rated high enough to handle the power. If you are transmitting into an antenna you can get very misleading results.
Regards,
Bob |
RCI 2990
| | Posted on Friday, August 01, 2003 - 1:40 pm: |
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My 2990 got out like no other but it did nowere near 300 watts! Put that bad boy on a average reading meter and it will not do the 300 you claim i guarantee! I dont like bird meters and wouldnt have one given to me but if you know a guy that has one have him put the radio on it and it will suprise you what the radio is doing!!! |
ryan
| | Posted on Saturday, August 02, 2003 - 12:20 pm: |
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maybe 1/2 of that 300 watts is in harmonic and spurs. careful there chief |
Kc0gxz
| | Posted on Saturday, August 02, 2003 - 11:23 pm: |
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Cobra0020
It is possible that your radio will indeed do your claimed 300 watts possibly on sideband. But ONLY if the finals in the amplifier have been changed to a pair of 2879s and a MUCH BEEFED-UP power supply has been added.
The stoch 2290s that come with that radio are not capable of 300 watts especially when driven with the single driver that is in the 2990.
As ChillyDog stated in his post, a dummy load IS A MUST when checking true RF output. NEVER check it into an antenna. Too many variances there.
Jeff, kc0gxz. |
2600
| | Posted on Sunday, August 03, 2003 - 3:03 am: |
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Umm, the meter lights aren't, like, REALLY bright, are they? Sounds like the power supply regulator is getting ready to visit Suicide City, maybe?
Or did someone do a "power jump", running the radio from the regulated voltage, but the linear from the UNREGULATED (20-25 Volts) side? That red teflon wire that feeds power separately into the linear at the rear has proven irresistable to a few wattmeter hounds. Makes a bottle-rocket out of the radio. VERY impressive performance, very brief, too.
Sure, it could be the wattmeter. Have you compared this meter to another, or tried another meter on this radio? If not, how can you tell? A radio doing roughly double the normal power sure sounds like "power jump" territory to me.
73 |
Reddog355
| | Posted on Sunday, August 03, 2003 - 12:00 pm: |
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Hey guys,I went to cobras house and put that bad 300 watt 2990 on my dosy tc4002psw and it showed about 150 and at times befor it warmed up it show a little more but i told him to get a new meter and he needs to tell the other person that checked it (moccasion) to get a new meter to
Reddog |
RCI 2990
| | Posted on Sunday, August 03, 2003 - 2:11 pm: |
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Those Dosy meters can be booted up to show big watts from inside. Its a truckstop trick thats used a lot in some shops... I was messing with mine once and got my 2990 to show 500 watts swing on my meter. |
Kc0gxz
| | Posted on Monday, August 04, 2003 - 1:53 am: |
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Reddog355
It really makes no difference whose or what meter you use. The fact still remains that a pair of 2290s and especially with that radio's power supply is NOT capable of 300 watts.
2290s will die BEFORE they see 300 watts even at 16 volts. It's something like saying that a Cobra 148 has a power output of 65 watts with it's stock 1969 final.
Like Bullet said in his earlier post, the 2290 is rated at 80 watts. The very best you could possibly see from a pair of them would be "MAYBE", and I do mean MAYBE is 175 watts peak. Ryan's post makes a lot of sense too.
Also, using a Dosy ego meter tells me a lot right there. And I bet you still didn't check that RF power into a dummyload like the others and myself suggested in earlier posts.
Did you check his SWR? ANYTHING over a 1.1-1 WILL be a incorrect RF Power reading. And besides that, using your antenna for taking power readings is a poor choice because your antenna will never see 100% of your transmitted power. As SWR gos up, performance goes down. That's one of the reasons why some antennas are better than others. And some of them NEVER see a flat SWR no matter where in frequency you go.
Lets face reality here. No matter how much voltage you put to those 2290s or how hard you drive them, they will NEVER see 300 watts. A pair of 2879s, yes, that's what they were made for. A pair of 2290s, no, that NOT what they were made for.
Take Bullet's and ChillyDog's advice and then check it again. Check it into a GOOD meter with a GOOD load behind it.
73s
Jeff, kc0gxz. |
Reddog355
| | Posted on Monday, August 04, 2003 - 8:23 am: |
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ok i dident mean to start a big meter thing here,but the dosy was the one that showed 150.I purchased it through copper a few years ago.It also showed about 45-55 RMS watts from a 10 watt dead key and no we did not use a dummyload we went through the antenna.His palomar meter he was checking it with has screws to adjust that kind of stuff on the back of it,he also just got it and it is very old so i am guessing that someone has been playin with them and pumped up the meter a little bit.And by the way i never buy a used meter, i like to get them new along with most of my other stuff so i no noone has mest with it.I donot beleive copper is going to tune up my dosy for me before they send it(at least i dident ask them to LOL)I just posted to let u no the radio is doin what it is suppose to be doin.
Later reddog |
RCI2990
| | Posted on Monday, August 04, 2003 - 2:32 pm: |
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Theres no way anyone can get a flat match with ANY antenna! Even the I Max 2000 that you guys think is so wonderful. I had one and i still never had a flat SWR... The meter deal is all overrated anyways. Meters are a device made for reference only and way to many guys take meter readings as gospel along with the fact that they think a bird meter is the most wonderful thing on earth!! Geezz, So what!!! Id never own a bird meter even if someone gave one to me but thats JMHO. The meter is the VERY last thing i worry about in my radio setup. As long as i am getting out and everyone can her me and i have a good SWR (below a 1.5) and my modulation is loud hey im a happy camper!!!!!! |
Taz
| | Posted on Monday, August 04, 2003 - 8:01 pm: |
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The only meter I need is an swr meter.
And maybe a modulation meter so I know my mic still works, lol. |
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