Thread: CB Linear Amps
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Old 07-12-2010, 12:15 PM
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DaveInDenver DaveInDenver is offline
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Join Date: Jun 2006
Location: Larimer County
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Originally Posted by thefatkid View Post
Little OT, will those Linears work for people with HAM equipement?
In theory yes, you could potentially use an illegal CB linear amp for ham and it would become a legal piece of gear. This falls under the implicit understanding that hams are allowed and really expected to tinker with gear. You can take any piece of radio gear and use it for ham; commercial, kits, home-made, it's all perfectly acceptable for amateur radio.

There are a couple of caveats, tho. First, that gear can generally never again be used for its original service (e.g. liberated commercial gear that is used for ham can never again be used for commercial) and second it must be certified to meet the technical requirements deemed necessary the F.C.C. and by your fellow hams. If you are buying a piece of gear, the manufacturer tested it and asked the F.C.C. to verify it's acceptable, but if you build or modify something it is you who is giving the gear the thumb's up under authority of your ham license.

What it means to 'meet requirements' is that to the F.C.C. it stays within our designated frequency spectrum, so it stays on frequency and does not create more interference than allowed, both within and outside the ham bands. To your fellow hams by using a piece of gear you are further saying that your radio junk will not splatter or deviate to the point of being annoying. The requirements we place on each other go beyond (or are really complementary to) what the F.C.C. asks of us. IOW, you could have a piece of gear that is noisy but stays within the ham bands and could be therefore potentially legal but still unusable as a favor to other hams.

Think of the ham bands as small, virtually walled RF sand box that the F.C.C. basically says we're allowed to play in as long as we don't get sand outside the edges of the box. What sorts of sand castles we build inside the box are up to us to more or less self police, which is why we come up with things like band plans and suggested frequencies for modes. There is no legal requirement that repeater frequencies end up where they do, that is by handshake agreement amongst all hams. Same with using voice or Morse in certain locations, set aside parts of bands to use only for satellites or using SSB or FM at others.

The bottom line is that you could buy one of these amps, modify it for use on 10m or 12m (they are designed for CB, which is outside a ham band) and it may be fine. It might even work without modification, in that it may amplify a 10m input. What probably will happen, though, is that it will create interference that makes it illegal (by creating noise outside our bands) and discourteous to use (off frequency, lots of harmonic noise, etc.). It would be up to YOU to guarantee that it is working properly. But for 10m in particular all these illegal amps do create a cheap source of the guts of amps for us hams, but the designs and quality of them leave a whole lot to be desired, so you have to be very careful with them. They are also generally made extremely poorly, so you also need to be careful that they aren't dangerous. Above about 50W you have to be aware of RF exposure and burns.
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