Copper Talk » Open Forum » Archived Messages » 2003 » 11/01/03 to 11/30/03 » Mobile units in the house and tvi « Previous Next »

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mikefromms
Posted on Wednesday, November 19, 2003 - 11:33 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I notice that my new base station DX2517 (as if you all don't know by now) does not interfere with my tv. Well, just barely on some stations but just a little line. But it is nothing like the mobiles I had hooked to power supplies on the same antenna system. Even with a tvi filter my mobiles still got on channel 2 and 4 pretty good at times. Maybe I forgot this, but do the base stations come equipped with better built in filters to prevent tvi? What is your experience with mobiles in the house and tvi?

mikefromms
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Bruce
Posted on Wednesday, November 19, 2003 - 1:45 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

If they comply with FCC rules there should be no diffrence. However its always a good idea to run into a low pass filter. My ft-100d is a moble radio as is my dx-70 no problems with tvi even without filters but i run one anyway.
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Ca346
Posted on Wednesday, November 19, 2003 - 2:26 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I'd like to know the answer to that one also! I always run a seperate ground wire to the mobile radio thinking that helps with TVI. I have two filters tho. On the radio in the house, I use a Vectronics low pass filter. On the radio in the shop/garage I use a COPPER low pass filter. Both are grounded with seperate wires to a common ground.

No complaints from any neighbors! (yet?)
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Sparkomatic
Posted on Wednesday, November 19, 2003 - 3:14 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

You are not supposed to watch TV while you are driving so TVI is probably not an issue.
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Ss8541
Posted on Thursday, November 20, 2003 - 10:44 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

the mobile and bases use the same board, so there is no difference tvi wise. the bases have a built in power supply, and the mobiles don't.

as to what bruce said about radios meeting fcc specs, 10meter radios do not have to meet these specs. if you doubt my word, look on the back of any 10mtr radio. you will never find an fcc i.d. #. you will find this # on the back of -ALL- cb radios, but not -MOST- 10mtr/export radios.

to help answer your question, all legal cb radios must meet -60dbc or better for harmonics. most 10mtr/export radios are -50dbc or slightly better. this is all for 'from the factory' tuning. after someone has screwed with them, they will not meet this.
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Bruce
Posted on Friday, November 21, 2003 - 5:22 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

And as ss8541 knows if the radio only has to meet a -40 db spec a 4 watt radio will have .4 MILLAWATT of signal outside the band not much tvi there. I supect he's right its junk or TWEEKED radios not base or moble.
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Deadlyeyes
Posted on Friday, November 21, 2003 - 8:00 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

541 is correct...

CB, business band, public service and just about all radios other than the Amateur Radios are type accepted. Amateur radios are not type accepted other than a few general/very general guidelines. Amateurs can and the old timers often had to build and maintain their own radios with their own two soldering iron burnt hands.

No FCC type acceptance there.

You can still today build your own ham amp and radio if you wanted to. But the commercial radios are just sooooo much better.

Still I do kind of miss Heath Kits.

DE