now practice with cobra 148gtl or grant like this.
Example Alignment Using Scope and Freq Counter - YouTube
Example Alignment Using Scope and Freq Counter - YouTube
Ok everyone, with 1000hz tone from my Mic the first one is what I have from Am and the second from Ssb (lower I believe.)
I did some tinkering with the scope and correct me if I'm wrong but trigger its too keep the view from scrolling? In not sure what the tech term for that is?
Does this look correct? I don't even see a limiter trimmer for Am on this radio.. I see the one for ssb?
I can see with the tone the diamond shaped peaks and valleys look pretty symmetrical to me. I'm not sure what it's supposed to look like on side band.
Please everyone give me your constructive criticism as quick as possible, I'm going to leave it hooked up for now but I want our back in the truck tonight.
It's this the best I can do without npc? If I do the Npc what can I expect? Also one last question, should I lower the resistor on the carrier (am power) trimmer resistor to go even lower? I can really tell but I think it's less than 1 watt. Should I be higher when driving 2x 2sc2879 at 14.2 volts (roughly where it stays)
My lobes are leaning slightly leaning lol, how do I fix it
Well... hmmm..I used 20x 1k 1 watt 1% metal film resistors to make 50 ohm 20 watt d load, I have that on surface mount copper clad,I made this, it's inside a Hammond enclosure. The rf sampler.. lol is on copper clad, 2 ge diodes opposing to gnd, into 7pf into 47 ohm resistor into the other half of a cut bnc 50 ohm cable.. problem is, it's hanging from the cable from the d load not enclosed.. that could be the problem, but the power supply its a pc supply, not the best I know but it's all I got for now, I made an amc circuit trimmer bc this radio doesn't have one, it seemed to distort the signal more than help. I used a schotty diode tho, maybe not enough drop??
I also lower the resistor coming off the am power to 1k2. For better control of the carrier, . I might attempt the amc one last time with a regular switching diode..
I've heard of people lowering r131, will this get some more peak through?