"phil " wrote:

hi Eric:

the 1000' antenna was untuned, very capable of obsorbing MW energy,
directional, and aimed at a powerful MW station.

Quite true, but that's not what you said -- you said it was
"resonant." A nit-pick, perhaps, but you misrepresented several
things I had said and done in that message, and I do not take kindly
to that.

As for the "flamethrower" at the end of the wire, they are in
violation of 47 CFR 22.369, which explicitly lays out the field
strength limits on Table Mountain. They may get grandfathered in, but
now that the feds are reopening Table Mountain for NIST projects, the
local HDTV wannabes are chafing at the restrictions -- even though
their antennas would be about 40 miles away.

the R8B/R75 both
overloaded: too much first mixer energy.

But at very different signal strenghts and with very different
characteristics: The R8B overloaded abruptly -- switching in a 1 dB
step was enough to have it operating normally or overloaded. The R75,
by contrast, had this "mushy" signal strength area.

the R8500 did better due to its LW
BPF (100-500 kHz) and relays (vs PIN diodes).

Yes, but mostly I'm interested in the results of the design. Not that
I'm not interested in the design, but the implementation is what made
the '8500 immune to such things.

however, for NDBs a $50
homebrew LW loop, being tuned and directional [rotateable], reduces IP3
demands... any tabletop will suffice.

Well, if I rejoin the group that works out there and set up a loop,
I'll see if I can pick up the DFW OMs as cleanly as I could with the
wire.

Then I'll use my homebrew phaser with a loop and the wire. Probably
Pete's loop.

AFA ICOM, i care little. their errors were our gain: users get a $1050
radio for $450 and Kiwa fixes it for $80. if it were perfect i would not
have created three mods and done five.

I still think you think you got more than you really did. Just out of
curiosity, is that $1050 the original price of the R75? It was pretty
high when it came out.

i have 5 MW radios and often use a
portable. my limiting factors are external MW band noise [~10 dBuV at 1
MHz] and antenna related. i do look forward to Pete's MW receiver.

I do as well and will probably get one as soon as they're available.

regards,
phil

--
Eric F. Richards

"The weird part is that I can feel productive even when I'm doomed."
- Dilbert