Hi Marv, Gee, that feed forward correction method sounds like something that would be ideal for the FT-1000D. As you said, it could be later moved from rig to rig too. So far all I've seen on the web
Karl-Arne, OK on the caution needed regarding obtaining these high IMD numbers. Good advice, OM. I would say that the level of distortion I heard when listening to the 5mW level coming out of the FT-
I called some ham friends looking for 4CX-350's drivers for the tetrode linear project. One of the guys has some 8560A's, with sockets, heatsinks, etc. that I can swap some stuff for. These are the c
That's the info I needed, Steve! -30 db IMD at 300+ watts. Yes, as you said, the 8560's [4CX-250's] will be used as class A voltage drivers putting out barely a watt or two, and 30 volts of swing. Th
Gary, Yes, I've read that too, but then I've read the opposite.. That statement above would make my question about using a chain of GG tubes running at 1/10th reduced ratings a poor idea. I'm a litt
Very interesting comments. It certainly IS an eye opener when you see what each driver plate dissipation needs to be for an all class A chain. But an easy way to maintain high IMD figures. I'm consid
Please disregard my question below: "Would there be a major disadvantage to running the whole tetrode chain in GG with standard voltages on the grid and screen? It seems it would be much easier to ta
Just to keep the reflector updated with info... I received a few private emails regarding using a chain of hi mu GG tubes in cascade. The general consensus is that it was not a very good idea. One re
Hi Bob, Thanks for the suggestion. You make a good point of possibly eliminating the 6146 pre driver. I thought about that myself, but didn't have enough knowledge to know if I would have enough gain
Hi Marv, The 75M mono-bander: Well, it looks like your original driver from that Hughes amplifier with the 6146 driving the 4CX-250 is still the best way to go. Thanks for clearing up the stage gain
Generally, on most bands, we can "hide" in the band crud when the amp is between -25 to -30db 3rd order. This includes bands like 40M at night, 20M during a contest, 160M when the band is QRN noisy,
Hi Bill, I'll encourage the other guys answer the finer details of how NFB works... But, for every DB of negative feedback, you get a db of IMD improvement. And also, for every db of negative feedba
-- Some very good points in that last post and truth about the real world radios out there! What stands out to me is the Class A mode of the FT-1000MP and later rigs, etc. Their 200W amplifier can b
Here's a coincidence! I just received an email from a buddy who is considering buying an FT-1000MP. They are being closed out and discontinued according to a salesman. Here's the salesman's comments
-- Vely, bery interesting, Peter! I passed that info along to my friend who is considering the MP. With what particular rig was this a problem? I am also thinking of selling my highly modified FT-10
Hi Colin, That is some interesting info! I was not aware of the need for audio bypassing in the areas you mentioned. Also, I have always wondered about shorting the final's tank coil for band changes
Does anyone have for sale, or know of a source for the little gold clips that screw down to the chassis and hold a 4-1000A chimney and tube in place? [they also ground the tube collar - 4 used per tu