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Message |
    
Aircop12
New member
Username: Aircop12
Post Number: 7
Registered: 5-2004
| | Posted on Friday, June 04, 2004 - 3:10 pm: | 
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I am running a Ranger 2995DX with a KLV 1000P. I have (2) filters to install on this system to cut down on any interference I might cause. I would like to know the best place in the system to install these filters. I'm not sure if I need (1) between the radio& or if I should install both after the amp.
Thanks: |
Tech808
Moderator
Username: Tech808
Post Number: 2574
Registered: 8-2002
| | Posted on Friday, June 04, 2004 - 3:22 pm: |
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Aircop12,
Radio ~ Lowpass/TVI Filter ~ Jumper ~ AMP ~ Antenna.
OR:
Radio ~ Lowpass/TVI Filter ~ Jumper ~ SWR/WATT Meter ~ Jumper ~ AMP ~ Antenna.
You can use a DOUBLE MALE CONNECTOR to hook the TVI Filter Direct to the Radio which is what is recommended.
Part #C-70-05012
Click on the link below.
http://www.copperelectronics.com/cgi-bin/checkitout/checkitout.cgi?catalogSTORE:CKIE:prodC70-05012+
Hope this help's.
Lon
Tech808 |
Aircop12
New member
Username: Aircop12
Post Number: 9
Registered: 5-2004
| | Posted on Friday, June 04, 2004 - 7:23 pm: |
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Tech 808,
Thanks for the help. I will also be running through a receive amp,so.. I guess the best would be: Radio ~ filter ~ receive amp ~ dosy meter ~ 1000P ~ antenna. If this will work, just let me know.
Thanks again: |
Tech808
Moderator
Username: Tech808
Post Number: 2577
Registered: 8-2002
| | Posted on Friday, June 04, 2004 - 9:23 pm: |
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Yes this will work but make sure you have good jumper's as you will using three of them. 
Lon
Tech808 |
Allagator
Intermediate Member
Username: Allagator
Post Number: 309
Registered: 9-2002
| | Posted on Saturday, June 05, 2004 - 12:48 am: |
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humm TVI with a 2995dx and a KLV1000P i dont have nothing now im grounded good !!!!
but i can still talk on my alarm clock ???
Allagator |
Highlander
Advanced Member
Username: Highlander
Post Number: 523
Registered: 12-2001
| | Posted on Saturday, June 05, 2004 - 8:43 am: |
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I would put the filter AFTER the amp.
Radio>Receive amp>KLV 1000>Filter>Wattmeter>Antenna
I think running a second low pass filter after the radio is a waste of time and signal. Not worth the insersion loss you will get. If the low pass filter between amp and wattmeter is a good quality one, it will cut off any harmonics in your signal, regardless of where they were generated, radio or amp.
Just my opinion. |
Tech808
Moderator
Username: Tech808
Post Number: 2581
Registered: 8-2002
| | Posted on Saturday, June 05, 2004 - 10:18 am: |
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I use the MTI LM-TVX2 filter's now and have used MTI Filter's for over 25+ year's, with Excellent result's
Below is the link for there site with instruction's on Mounting for best result's.
http://mtifilters.com/mtifilters/LMRFI.html
From there posted information on the MTI Site.
A Low-Pass Antenna Filter used to control Harmonics and TV/FM Interference from CB and Amateur Radio Transmitters operating below 30 MHz.
Any normal CB or amateur transmitter can easily interfere with television and FM reception in its immediate area. The primary cause of this interference is that the transmitter radiates low-level harmonics which fall right into the TV/FM band.
The cure to this problem is simple. Install an LM-TVX2 low-pass filter in the transmitter antenna output to provide additional harmonic reduction.
The LM-TVX2 is an improved nine-element low-pass LC filter designed for use with transmitters in the 160 to 10 meter bands. This filter cuts off at about 45 MHz. The LM-TVX2 is not intended for transmitters in the 6 meter or higher frequency bands. The maximum power rating of this filter is 1KW AM, 4 KW PEP or 400 W CW rf output on a 50-ohm coax line with a VSWR under 3:1. Insertion loss is under 0.4 dB below 30 MHz and attenuation is on the order of 50 dB through the TV/FM bands above 50 MHz.
The LM-TVX2 should be located close to the transmitter. It may often be mounted directly on the transmitter output connector using a double-male adapter and possibly an angle adapter as shown.
Make sure the antenna or coupler is adjusted for an acceptably low VSWR in the output line before installing the filter. At frequencies of 30 MHz and below, the filter acts like a short additional length of transmission line, and won't change the transmitter tuning and loading adjustments much if the VSWR is low. If difficulty is encountered in readjusting the transmitter, lengthening or shortening the antenna cable by about a quarter wavelength (9 feet on CB) will usually solve the problem.
_________________________________________
With less than a 0.4 Inseration Loss I never noticed a difference.
Just my result's with mounting TVI Filter's direct to my radio's.
Lon
Tech808
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Highlander
Advanced Member
Username: Highlander
Post Number: 525
Registered: 12-2001
| | Posted on Saturday, June 05, 2004 - 1:38 pm: |
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The point I was trying to make is that if you are using an external amplifier, the low pass filter should come AFTER the amplifier, not before it. There seems to me to be no benefit to running a second filter between the radio and the amp. The one after the amp will take care of any harmonics above the cutoff frequency, so why put a needless .4 DB of attenuation in to the mix, if it has no effect on the signal reaching the antenna?
Your post does not mention anything about needing two identical filters in the same system, does it?
I'm saying that if you have one after the amp, you DON"T NEED the one attached to the radio.
If you are not running an external amp, then putting the filter on the radio makes sense. If you ARE running an amp, then it does not make any sense to me.
Hope that clears it up a little... |
Tech808
Moderator
Username: Tech808
Post Number: 2587
Registered: 8-2002
| | Posted on Saturday, June 05, 2004 - 6:04 pm: |
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Thank's,
I guess I have been blessed or very lucky as I have just never had to add one after an external amplifier before or had any reason to run two of them in line.
But I can see where some people might have that problem and one mounted direct to the Amplifier would help.
We run the KLV-1000 and the KL-300P & KL-500 Mobile's off of Power Supplie's and have not had any problem's so far.
Lon
Tech808 |
Tech833
Moderator
Username: Tech833
Post Number: 724
Registered: 8-2002
| | Posted on Saturday, June 05, 2004 - 9:22 pm: |
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Using a filter between a radio and an amp will prevent you from amplifying the harmonic along with your signal. That makes your amp run cooler and more efficiently. Using a filter after the amplifier rolls off all the harmonic content headed for the antenna, and is highly recommended. Using two filters is fine. Broadcasters do it all the time between the exciter and IPA, then another hrmonic filter on the output of the PA. |
Aircop12
Junior Member
Username: Aircop12
Post Number: 10
Registered: 5-2004
| | Posted on Sunday, June 06, 2004 - 10:02 am: |
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Ok, thanks for all the advice. I will try it with (2) and see how much loss I get.
Thanks again: |
Tech833
Moderator
Username: Tech833
Post Number: 730
Registered: 8-2002
| | Posted on Tuesday, June 08, 2004 - 4:55 pm: |
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Should be less than 1/2 dB, even with 2 filters. Well worth the loss. |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 174
Registered: 7-2004
| | Posted on Sunday, August 15, 2004 - 2:16 am: |
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Where can you find the LM-TVX2? I did an internet search and couldn't find it for sell.
Thanks
Bob |
Tech808
Moderator
Username: Tech808
Post Number: 3302
Registered: 8-2002
| | Posted on Sunday, August 15, 2004 - 4:27 am: |
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Copper is awaiting shipment from the Factory on them.
As soon as they arrive i will make a post on the New Product.
Lon
Tech808 |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 177
Registered: 7-2004
| | Posted on Sunday, August 15, 2004 - 3:48 pm: |
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Thanks Lon I was saying I have a B&W 425 but it raises the SWR quite a bit. Right now I have a 1.1.1 SWR at 27.385. I don't know if that is accurate since it rained yesterday, but when I put the B&W on it went over 1.6.1 so I took it out of line. That said if the SWR is a false reading and the SWR is closer to 1.5.1 then I would think the B&W would cause the SWR to raise well over 2.5.1 anyway. But I could be wrong I'm sure no expert, and have had alot of problems getting this new station set up and running as you well know.
Thanks as always
Bob |
Hotwire
Advanced Member
Username: Hotwire
Post Number: 591
Registered: 1-2005
| | Posted on Monday, September 26, 2005 - 12:40 pm: |
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Found this thraed and has answered most of my questions. So to tech 808 or 833, it is not really necessary to have the filter on the amp but on the radio. Since the radio produces the harmonics and not the amp this makes a lot of since to me. I will try it with the right angle adapter on radio so it will be radio, filter, jumper, amp to antenna like you have yours 808. I will let everyone know what results I get! |
Cornbrown
Member
Username: Cornbrown
Post Number: 55
Registered: 7-2005
| | Posted on Friday, October 21, 2005 - 2:39 pm: |
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Hey Hotwire How did the test go??? |
