Search results

Thank you sir, sounded good in my undermodulated Cobra 2 grand, no doubt about it.... Toll_Free, cruisin this small driver 'round 6 thousand feet above these killin fields, I got down......

If you want 60, 78/80 and 160, then you need to get a new amp. OTHERWISE, what you have will work FB, with a bit of work. --Toll_Free

1. Odd order harmonics are going to be through the roof. I really hope you don't have any 75 mhz to 90 mhz stuff in your area actively being used. 2. Ameritron and other mfgs, as well as Messenger (A CB linear company) either have, or are coming out with, bandpass filters that are...

I like the 4 2879s running on a 35 amp power supply. How many watts of distortion did your wattmeter start swinging after the 2879s where put in it? 4 2879s need 80 amps PEAK. Hard to get that out of a 35 amp supply. And Toshiba rates them 4 'pills' at uh needin 100 (that's a hunnerd)...

I really don't mean to be a dick here, but a licensed ham for 42 years, and you can't look inside the covers and see if their is a diode clamp bias in it? If you HONESTLY want to put it on '10 meters', then first you need to destroy whatever CB bias circuit is in it, put in a real thermal...

Unless you mount a thermistor to EACH device, or pair of devices, you won't gain much by setting the bias independently... The reason being, you will be tracking HEAT SINK temp, which is a culmination of ALL of the transistors. That being said, I do put a single 6A10 from the bias buss to...

If it's a BLUE FACED Cobra, I'd keep that one. Better bias circuit. The XL350 blue face also has 10 meter filtering, IIRC. If not, keep the texas star. The bias can be made better. --Toll_Free

They really told you that? WHEN THEY MARKET THE AL811HD? Guess I'll have to dl a schematic and see if their are any other things they've done to the "572"'ed version of the AL811H.... Thanks for the info from Ameritron, tho... Won't recommend anyone to change them out again until I...

I'll bite. How do you measure grid VOLTAGE in a grounded grid amp? Interpolating from Cathode current, etc? I'm in the process of building a water cooled 3CX30K, but it's a VERY low Mu tube.... Meaning it has to be grid driven... AND it's a 'bolt in grid' tube, with flying leads for the...

Not a bad price on the Cobra 1000. It's a 29 with power supply. Looks like a 2000. Had I not bought another radio this week, Id'a picked up your 1000. I like them, look good next to the 2000s :) --Toll_Free

And a set of 572s in an amp designed for 811As will last 30+ years, barring idiots or catastrophic failures. I was REALLY surprised to see original 572s in a Gonset GSB-201 pile of frig I just rebuilt. It's an 811 amp, and the guy my customer bought it from ran the 811s for, as you put it, a...

1. I was posting a correction. I had misquoted the actual "theorum", went and checked it, and then posted a correction. 2. The numbers I quoted about my 3-500Z amplifier where so the person I was responding to could see the numbers actually DID make sense..... IE, 130 mils / .400 A...

Captain KayDub.... I do have to restate what I was saying earlier, I had the actual order of the elements in the tube wrong... The 3/2 law is the ratio of grid VOLTAGE to plate current. In a LINEAR amplifier. Off in left field earlier.... BUT, take a look at a properly running...

Your guru Rich has explained it many times. When a Grounded Grid amplifier is amplifying as a 'linear device', the plate current will be 3/2 as a ratio of the grid current. Maybe this should go under the "how to tune a tube amp"..... Not many people, ham's or CBers can actually load an...

You're not too far off... Maybe need a bit more tuning (loading) to get the desired results. Do yourself a favor (and this goes for everyone running a linear that has grid and plate current meters) and read up on the "3/2 power law" or "3/2 ratio". It will explain what, in a grounded grid...

Neither the sweet sixteen nor the messengers will go down to the bottom of 80 with full Pout. I own a M2000, a converted M4V (converted to a pair of 455s driving 8 2879s... Combiners will NOT hold up, started a fire in it, and I keep it a a conversation piece), a M1200, Sweet Sixteen, Hot...

And OBVIOUSLY you can't differentiate between tongue in cheek and actual facts..... Sorry to confuse you. ALL my posts where made to point you to actually buying real tubes, rather than almost 80 year old technology. 40-60 years > 60 - 80 years. --Toll_Free

I couldn't tell you, Craig. When I put a tube in an amp, it lasts > 20 years. trying to tell me you made a "good decision" by purchasing some "spares" that are > 20 years older than the originals is........ BUT, to each his own. To tell someone that actually works on this stuff for a...

The factory recommended tubes for an AL811 or AL811H are the 572s... Just read Ameritrons BULLSHIT "spec and sales" sheet. AL811s are > 60 years old. 572s > 40 yrs old. Which one is "solid state"? --Toll_Free