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I'm not sure I agree. The SD1446 might not be the absolute best choice for linear operation, but very often the linear performance of these types of transistors is surprisingly good. I've even seen power MOSFETs intended for switching applications used as RF linear amplifiers with surprisingly...

There is a bit more to it than just snatching up a dave-made or whatever, hooking it up and yapping on it, that's for sure. It's best, when choosing an amp, to use class AB only for HF, including CB. You can read or ask around for info on CB amps known to be class AB. I also recommend using a...

That's right! the limit is 1.5kW PEP with a license, and 12W PEP SSB/4W AM on CB without one. That's 12W legally of course, obviously lots of CBers run power, and personally I don't care if a CBer wants to run a couple hundred watts from their rig.. I don't even care if they want to run a couple...

Not very

Well, as an Amateur the legal limit in the US is 1.5kW. 500W isn't but 1/3 of that, so it's perfectly acceptable to run if it's clean. I'll never use an amp that doesn't have good filtering, and I don't overdrive so the IMD is kept in check. There are times when QRO is a good thing, and there...

That sounds about right.. Henry Radio out of LA sells these little BeO ceramic attenuators. My plan would be to integrate one into the input of the amp so that higher drive can be applied, with a max of roughly 1.5W being allowed through the attenuator for a specific input.

WOW!! 125:1.. that's amazing! I thought the 65:1 that the Freescale device withstands was impressive.. I actually just received an engineering sample of the MRF6VP11KH: MRF6VP11KH Product Summary Page It's not as rugged (10:1) but it looks to be useful nonetheless.. they're not offering samples...

Actually, I've been looking at the Flex 1500. I think I'm going to try the SDR route.. I've been using a friend's 817, and I like it, but the software defined stuff fascinates me.

^Good eye!! I totally missed that.. You are correct, they're posing for the picture only. Plus it was around 1:30AM when I took that pic. I was a little tired lol..

I got a lot more done tonight than I had planned. The board is complete except that the MRF454s are just sitting on the board for the photo. They won't be soldered in until the board is mounted on a heatsink. For detailed info on the construction process see here. LPFs are next!

here's my newest acquisition: A complete set of parts for the EB63 amplifier (2xMRF454 class AB), which is rated for 140W PEP output. I got it for a song ($60) on ebay.. plus as a bonus it included 2 Communications Concepts low-pass kits for 20 and 40m. Not a complete set, but way better...

I've always had some reservations about the ability of HAARP to control the weather. I'm not a meteorologist but I'm pretty sure that there's a whole lot more to the weather than what ionospheric conditions contribute. HAARP's whole point is to explore the ionosphere and manipulate it.. that...

10W PEP is the recommended maximum input yes, but quite often some of the input power is lost in the input circuitry of the amp. When you select low or medium power, for example, the input signal is cut back by the input circuitry in the amp so that the output is lowered. The only time that...

^Very true, this thread is about a 148, and really at the power levels achieved by the final in that radio (or even an upgraded/modded final PA circuit) any spurious emission will be small enough in intensity that it shouldn't be overly harmful. It's mostly the bigger stuff like amplifiers and...

^See, now this is where you don't know as much as you think you do. All the "outlaw" in the world doesn't change the laws of physics, sorry. I'm not saying this stuff just to blow off hot air. There's a lot more to this than you are understanding. I know this because you keep insisting that...

So basically what you're saying is that you've been to several forums acting like you have here and they've all banned you? Imagine that... Here's the deal: Your mindset regarding 11m operation is garbage. This is not an opinion, it's scientific fact. You (and all operators) need to eventually...

The people you TALK to on CB bands do not know what a clean signal is 90% of the time. They are entirely unaware of things like IMD and harmonics, but experienced and knowledgeable people know and understand these things. You cannot "hear" harmonics in your signal as they are not even on the...

Many thanks superdigit! I enjoy this kind of DIY stuff immensely.. in fact I have procured a complete set of parts for the EB63 amplifier (Motorola 2xMRF454 140W PEP class AB amplifier) for a very good price, so a thread will be popping up detailing it's construction soon. I'm happy to hear...

Hmm.. I was under the impression that bigal has a different unit than the standard 203. I'm assuming there is a difference between the KL-203 and the KL-203P.

Well, without a clear picture of the guts to see it's pretty hard to say. RM does not have a schematic on their website, so it's impossible for me to say what's inside it to try to get an idea of what could be wrong. Based on the information at hand it sounds like you have a defective unit. I...