Copper Talk » Ask The Tech » Radio's Mobile » Archived Messages » Swing question « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Audiophile73
Junior Member
Username: Audiophile73

Post Number: 17
Registered: 5-2004
Posted on Tuesday, October 26, 2004 - 12:09 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

ok im a little confused. I was always taught the 1 to 4 rule. So a 4 watt dk fully modulated (100%) would be around 16 watts. Ok, so if I turned down my radio to a 2 watt dk it will swing to around 8 or 10 watts. That makes sense to me, but how do these radios get a 1 or 2 watt dk and swing up to like 16 watts. How are they not over modulated.
Top of pagePrevious messageNext messageBottom of page Link to this message

Audiophile73
Junior Member
Username: Audiophile73

Post Number: 20
Registered: 5-2004
Posted on Tuesday, October 26, 2004 - 9:28 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

o c'mon
Top of pagePrevious messageNext messageBottom of page Link to this message

Patzerozero
Intermediate Member
Username: Patzerozero

Post Number: 167
Registered: 7-2004
Posted on Friday, October 29, 2004 - 6:45 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

there's a little screw under the wattmeter's window to adjust the zero setting. if you turn it up you can increase your output.
well i'm sure some shady tuners have tried it.
i'm sure a lot of claims are exaggerated, as well as meter tolerances/inaccuracies etc. and there's really no noticable difference in 12 or 16 watts swing or 3 or 4 watts dead key. there's fancier mods out there such as adding dual finals, changing the original final, npc-rc, if you're handy w/a soldering iron and want to see what you can do to a radio, as i do, that's all fine and dandy. but there's always someone who has more, has done it better, etc. as long as i'm loud and clear sounding locally, i fire up the ole amp to get out when the skip's rolling.
as for 1 or 2 w swinging 16 if you're referring to a standard cb, i'd take it w/ a grain of salt.
a radio such as magnums, transmit/audio was designed from the ground up to key 1 swing 40 and is probably not able to be duplicated effectively.
of course, in my experience, whatever magnum did to get that output turned it into a tvi machine, i've managed to minimize it, but it gives me more tvi problems than my 150w ar3500 and my grant xl w/texas star 350 on base.
Top of pagePrevious messageNext messageBottom of page Link to this message

Inspector
Intermediate Member
Username: Inspector

Post Number: 100
Registered: 12-2001
Posted on Sunday, October 31, 2004 - 3:22 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

The 4:1 ratio is a target that is used that gives the best wave-form without distortion or TVI, in an NPC-RC modification. This also keeps the stress level low on the semiconductors (just think how rough a 1W swinging 40W could be on a semiconductor! ) Don't forget, your stock radio is set to standards and those standards require that the manufacturer keep the signal within limits, and to do this, it requires there be a stable carier that changes little with modulation. So, without modification, just turning down the watts only results in a smaller carrier signal modulated the same ratio. Overmodulation exists when you defeat (or mis-tune) the AMC and the modulation-peaks attempt to exceed the limmits of the carier-envelope. This results in the peaks flattening, or clipping, causing audio distortion and RFI. The NPC-RC mod reduces the carrier and alows increase of the carrier when modulation is applied (similar to what happens in sideband only not too such an extent). It is best to have the modulation initially tuned to no more than 100% before performing the modification, otherwise even this modification will easily overmodulate...defeating its purpose. I hope I didn't get too technical but I think it answers your question.

Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: