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 on: Today at 01:03:14 PM 
Started by KA3EKH - Last post by W2PFY
Will be interested to see what some of the “hard core” AMers have to say about this line of thought.

Well if 40 opens up this winter and people start using 7.290 & 7.295 or 7.293 on a regular basis, you will have no problem having people telling you what they think on ssb at the high end of 40. You'll probably be a popular as someone driving a buss at high speed on a city sidewalk. It won't have any effect on me since I won't be operating there this winter and I personally can't complain since it on a first come basis and is legal to do so. But you did ask Grin Grin  It would probably work great at night. I wonder if this will encourage other ssb people to operate the upper area without regard to a gentleman's agreement that someone said is in place?

 on: Today at 11:47:12 AM 
Started by AJ1G - Last post by WB2EMS
Thanks, it did. Not that Rhombics were really a desire - just a whim based on the possibility of significant space around a possible new QTH.

 on: Today at 11:09:41 AM 
Started by W4RFM - Last post by w8khk
Instead of three 6146 tubes, may I suggest a pair of 4D32 bottles?  They strap with moderate plate voltage!  You might also consider a cathode follower driver (6080 or 6AS7) for the modulators, and run them a bit into AB2.

 on: Today at 10:30:49 AM 
Started by W4RFM - Last post by W4RFM
So if I am going to put the 6CA7's and transformer to use, it looks like I should build an "improved" Apache clone, maybe add a third 6146 (as Wireless Girl suggests), and run everything the way Benton Harbor planned it. 725V on the modulators and 600 on the 6146's. Yes, no?  I just want a little something to check into some nets with.

 on: Today at 01:33:54 AM 
Started by AJ1G - Last post by K6JEK

... rhombics are probably not an option with the layout  ...

Maybe this will make you feel better about no rhombics: https://www.w8ji.com/rhombic_antennas.htm

 on: Today at 12:44:46 AM 
Started by G8VOQ - Last post by Opcom
some more

Surrey Electronics AM synchronous detector manual 1988
GE Ham News Vol 03 No 6
GE Ham News Vol 06 No 4
Popular Electronics April 1982

haha well so much for detectors, are there more to study?

But the OP was about 'detection' and AGC, so what articles might there be on lowest distortion envelope detectors, and how to get AGC voltages and use them?

There are a lot of other good receivers that have no AGC, like the Rycom R1307A. Applying AGC may be more complicated add-on due to differences between sets and some sets not having reasonable RF or IF gain controls.

There is this AGC but it's op-amps, not sure how it might apply to the original post.
KA9NEH, Fred Baumgartner., 73 mag SEP 1990

 on: Yesterday at 11:29:04 PM 
Started by W4RFM - Last post by DMOD
The 811A really performs better at ~ 1300 volts in Class C.

The other question is, does the Apache Mod transformer have the insulation capabilities for 1300V with respect to ground? Does the Apache Mod transformer have the insulation capabilities for 900V with respect to ground?

Either way, I think I would insulate the Mod transformer.

With ~ 73% Efficiency, here are two possibilities:


 on: Yesterday at 10:54:18 PM 
Started by W4RFM - Last post by KK4YY
The even bigger question is will you be able to modulate to 100%.

The Apache mod xfmr has a 3.66:1 impedance step-down (11k to 3K). That's a 1.91:1 voltage step-down (square root of impedance ratio). With 750 volts on the mod 6CA7 you may get ~1200 volts swing. Stepped down by 1.91:1 that's only 628 volts. You'll need 900 volts to hit 100% modulation.

I learned this here:


 on: Yesterday at 09:27:42 PM 
Started by WE1X - Last post by WE1X
Still available. $300 pick up or delivered within 100 miles of the Philadelphia metro area.

 on: Yesterday at 08:48:38 PM 
Started by W1KSZ - Last post by W1KSZ
Found it, many thanks.

73, Dick, W1KSZ

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