low pass filters

[rev ike]

has any one had any experience with low or hi pass filters i picked up an old ef johnson 250-20 filter at a ham fest it appears un touched i tried it seems i lost about 5 watts never had any complaints before but want to be sure

[BtyMONSTER]

i dont know about that filter but apparently its working . put a low pass filter on a 2x4 amp and see the watt difference . the couple of hundred watts that the amp will be reduced by is splatter that isnt even in the frequency that youre trying to transmit in . those watts contribute greatly to bleed over and RF interference to other electronic devices nearby ( tvs',computers',phones',neighbors and sometimes even vehicle computers) . how much power did you have b4 the filter ? any complaints with the filter .

[rev ike]

no complaints with the filter, just wanted to know what experiences others have had with them.i got this filter for a song and a dance i ran it earlier tonight with a couple of bushels,didnt know the computer was on when i asked the yl did i come through she said no. a week ago the same thing happened before the filter the 44 came in saying the computer is freaking out! so at that ill say its doing something.im still trying to get them to let me know when there on so i wont key but ...

[dud muck]

has any one had any experience with low or hi pass filters i picked up an old ef johnson 250-20 filter at a ham fest it appears un touched i tried it seems i lost about 5 watts never had any complaints before but want to be sure

One thing about watt meters, they don't discriminate between harmonic power and your 27MHz signal.
So if you have really strong harmonics (54 & 81MHz, etc), the watt meter reads those, sometimes called "false watts". Then when you put the filter in, the harmonics are knocked out and you only read your 27MHz signal on the watt meter.

And by the way.. usually those filters have power loss of about 5% of your CB signal, but harmonics should drop much more than 30dB.

[DX47]

You will loose power on a trashy amp, but thats wasted power anyway, usually being transmitted around 55mhz, right around TV channel 2.

[djrebel236]

i use

[linx]

I absolutely HATE the para dynamics low pass filter. What a piece of trash. It's made out of some cheap materials and for me didn't work if I ran over about 10 watts.

If you want a real low pass filter, spend some cash, and use what a ham would use....a Bencher YA-1.

As with any LPF, they're not going to work if you're using bad harmonics equipment.

You get what you pay for. I didn't even try to sell my para dynamics filter. I just threw it away.

[doctor]

I have a bencher works like a champ, money well spent, I got it used on one of the ham classifieds for $20 works great no complaints from anyone.

DOCTOR

[loosecannon]

agreed 100% on the cruddy para-dynamics filter.
its not worth the metal its made of.

to get a good LPF, you need to spend 50+ dollars.
good deals can be had on ebay.
nye-viking, bencher, and drake all make very nice ones that you can find every day on the bay.

i run a drake and always have. love it!

people dont seem to like to spend money on this type of stuff.
seems that if it doesnt make the radio put out more power, they dont want it.LOL

i know guys here that run 400 dollar radios, and use cheap radio shack coax jumpers. pure @$#%!

my antenna cost 50.00,
and my coax cost 75.00.

one of the best investments i ever made was upgrading to LMR400.

if anyone here is experiencing a TVI or RFI problem, and is considering buying a LPF to help; dont bother unless you are running good quality coax with a single unbroken run to the antenna already.
cheap coax has been the cause of many a noise problem, but again, people dont seem to like spending money on this stuff.
go figure.
loosecannon