Copper Talk » Product Reviews » Amplifiers » What is the best Amp with the LEAST TVI ?? « Previous Next »

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Creator
Posted on Monday, January 19, 2004 - 8:37 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hi,

I'm looking for a base amp with the following criteria in this order.

1- LOWEST TVI
2- NO BLEED-OVER
3- Audio left as clear as non-amp use.
4- AM/FM/SSB
5- Variable Power (like a knob I can turn)
6- Must be a base amp
7- AM power 250-600 watts SSB???

Thats it.. I'll be happy with that.

Thanks,

Creator
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Ca346
Posted on Tuesday, January 20, 2004 - 1:29 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I HIGHLY recommend the COPPER KL-500, I know you said a base amp, but if you already have a 12V power supply as most radio hobbists do, then it leaves you the flexibility to use it mobile someday. The amp is high quality and operates without me even remembering that its there.
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Keepitreal118
Posted on Tuesday, January 20, 2004 - 8:17 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Tvi has a lot of factors. Antenna hight is very important, grounding, coax, thiers just a bunch of things to give you tvi. Tubes would probably be better than transistors. Are you in a house, apartment, how far are the nearest neighbors?? A low pass filter may be a good idea.
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Tech808
Posted on Tuesday, January 20, 2004 - 11:32 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Have had NO PROBLEM's with the KLV1000 and TVI.
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Creator
Posted on Wednesday, January 21, 2004 - 5:47 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Re: Are you in a house, apartment, how far are the nearest neighbors??

In a house decently set back from most houses on all sides. I plan on mounting a Imax 2000 w/ GPK at 36' so the tip will be exactly 60' high. I already ordered a DX 95T, its in transit. I also unearthed my TRUSTY Turner +3B, very soon I'll be ready to rock! I'm also going to get that flexible Belding coax 100% sheilded, double sheilded stuff. Will order a good lowpass filter too. Also looking into good grounding technique.

Basically I want to operate free from causing interferance to any neighbor. So I can kick back and relax, & enjoy my hobby in peice.
Cant wait to get back on!

Creator
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Highlander
Posted on Wednesday, January 21, 2004 - 7:28 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Sounds like you've got a good plan. Grounding solves alot of potential prolems with RFI, maybe more so than a low-pass filter, but one is still a good idea. Keep you radio operating clean, watch the mic gain, and you should be all set!

A KLV 1000p would be a nice amp for that radio.
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Crafter
Posted on Thursday, January 22, 2004 - 12:00 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Well put you put a power mic on a radio and alot of times it just causes TVI, due to the audio.
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Creator
Posted on Thursday, January 22, 2004 - 8:17 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Re: I HIGHLY recommend the COPPER KL-500

Thanks for the tip.. Looks great..


Creator
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Creator
Posted on Thursday, January 22, 2004 - 10:46 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Got another question..

KLV-1000P

Input Power: 60-100 Watts
Output Power: 600/1200 Watts

Combined with the variable power knob on the Galaxy DX95T, am I locked in to transmitting at 600 and 1200 watts,, OR could I control the output simply by using the variable power knob on the radio. Is'nt this what LINEAR really means, power put in gets multiplied by a certain number then outputs higher.

thanks again,

creator
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Highlander
Posted on Friday, January 23, 2004 - 7:35 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Yes, you can vary the input power from the radio to control the amp's output, and the amp itself has variable stages of power as well.
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Gezus306
Posted on Friday, January 23, 2004 - 9:49 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Not only a good brand but what makes the most difference is :
NOT TO OVER DRIVE ! Invest in a good scope and tune to proper out put. Shouldn't have to
many problems from that combo.
( But there are still a lot more factors to consider )
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Creator
Posted on Friday, January 23, 2004 - 8:42 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Re: Well put you put a power mic on a radio and alot of times it just causes TVI, due to the audio.

With everything I've been reading about TVI and grounding and sheilding, this is the most important factor in TVI. Now we speak of high mic gain contributing to TVI dispite grounding the antenna and 100% shielded coax leads me to think... What is the weakest link in this senario.... The coiled microphone wire that connects my Power mic to the radio! How well is it sheilded, the mic has a 9 volt battery amplifying everthing I put into it, the microphone wire may be acting as a transmitter if its poorly shielded. I read that the better the sheilding on coax, the less signal leaked through sheilding and more power radiates from the antenna. Would'nt 100% sheilded microphone wire grounded to the radio make you louder (more signal getting to radio)and produce less TVI too?
Someone needs to test this and if it works, come out with an after-market 100% shielded mic wire to replace current ones on our power mics.

Just give me 5% royalties ;^)

Creator
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409
Posted on Monday, January 26, 2004 - 3:35 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

The sheild on the mic cord is mainly to keep stray signals from getting IN, not OUT.
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Keepitreal118
Posted on Monday, January 26, 2004 - 12:57 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Save your money on the ground plane kit. Doesn't do anything to the antenna. No matter what anyone tells you, it doesn't make it a TRUE ground plane.
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Bullet
Posted on Wednesday, January 28, 2004 - 7:09 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

i believe a ground plain helps, as well as a 1:1 curant balun at the feed point of the antenna. "also helps with tvi."

also good coax like lmr 400 or 9913f ect not any of the tiny stuff.

a clean radio free of harmonics to start with.
low pass filter,nice "real" ham amplifiers built for solid service and not just to turn a profit,antenna's high enuff to easily be out of the direct path of phone and powerlines helps greatly.

that antenna does not radiate rf just at the tip. 30 some feet is about the same height as the power and phone lines! id go higher if you have neighbors like 40-50 feet of tower.

rf chokes on your powercords to your radio equipment ect ect. you can get very into it if you really want to be clean.and its not real expensive and will help you out in your hobby as happy neighbors dont complain on your station.

stay away from transister base amps unless made be a big name ham brand. "like ameritron's al600".
those train builts exforce ect will bleed!

swing ratio's of 1:4 to 1:6 carrier to peak ratio
will also keep you cleaner,90-95 % modulation also keeps your tvi down.
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Creator
Posted on Thursday, January 29, 2004 - 11:47 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey Bullet,

Whats a 1:1 curant balun?

Thanks,

Creator.
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Adshar64
Posted on Saturday, January 31, 2004 - 11:32 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

A good tube amp beats solid state any day
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Lonestarbandit
Junior Member
Username: Lonestarbandit

Post Number: 47
Registered: 10-2006


Posted on Thursday, December 07, 2006 - 12:30 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

i have almost no tvi from the kl-203 mosfet amp and im in an apt complex. ;)
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Bruce
Senior Member
Username: Bruce

Post Number: 4215
Registered: 9-2003


Posted on Thursday, December 07, 2006 - 4:54 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

"A good tube amp beats solid state any day"

Not always true there are many good solid state amps just good ones cost money .....
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Hotwire
Senior Member
Username: Hotwire

Post Number: 2097
Registered: 1-2005


Posted on Thursday, December 07, 2006 - 4:20 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I agree with you Bruce. One thing cbers misunderstand is that it is not always just the amp that causes tvi. What you put in is what you get out but more of it. Radios with transmit mods, clipped componets, massive swing and no carrier,driving the amp into the ground, POWER MICS, etc, all contibute to the problems and made worse with cheapo amps and even high qaulity amps.
Start with a well tuned qaulity radio. Have its transmit power adjusted so that it just loafs while driving an amp and turn back the mic gain until you see your needle drop and then turn it back up just a pinch.
A high qaulity low pass filter is a must for any base setup also!

Then we have that front end over load which is not anything you can do but turn the watts down.

This is how I like to do it and get great reports and I am heard through out the land!
kenny
cef491
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Mrclean
Member
Username: Mrclean

Post Number: 51
Registered: 12-2003
Posted on Sunday, December 17, 2006 - 6:25 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I see this is an old post but my SB 200 works well and no problems with the people in the hood. 150 watts DK swings about 650 or 700. Runs good off 110 also
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Gator44
Junior Member
Username: Gator44

Post Number: 13
Registered: 1-2007
Posted on Tuesday, January 23, 2007 - 9:15 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I've got everything..I mean everything grounded and still have tvi problems! Aaaarh.. My imax is 56' to the base(well high enough)and no gp kit on it because i hear they don't work unless you're real low to the ground at the base. I "heard" you can at the base of the antenna where your feed line connects, take and make 5-6 3" tightly wrapped coils (and make a choke)in the feed line. Is this a very good idea? Does it hurt output power...swr's...etc? Help!! Thanks
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Gator44
Junior Member
Username: Gator44

Post Number: 17
Registered: 1-2007
Posted on Wednesday, January 24, 2007 - 1:13 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Okay, i fixed my TVI problem... Not for sure which one fixed the problem because i worked on two. 1. re-grounded my 696 and my skipper(which i think was the culpret), and i also made a choke on my cable coax(6 3" loops and zip tied)right before it goes into tv...and now no TVI even on high power!!
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Waverider
Member
Username: Waverider

Post Number: 63
Registered: 12-2003
Posted on Thursday, February 15, 2007 - 5:23 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Gator has the problem in hand. I have everything and I mean everything (starting with radios) right to the antenna well grounded and that cured my problem. Funny I lived in a neighbor hood years ago with no TVI problems. I how live on a farm with everyone spread out and I was still getting one of my neighbors TV. Now I can even run a "little help" and no problems even at my house. Gotta keep it that way cause you don't wanna pi** off the "boss"!!!!!!!!!!!

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