[Elecraft] K4 Question

[Eric Norris]

My neighbor is 714ft (218m) away, running an ic7300 at 100w into a ZS6BW
antenna at 40ft--aimed in my general direction.

73 Eric WD6DBM

On Wed, Jun 24, 2020, 12:12 PM Greg Troxel <gdt at lexort.com> wrote:

> Wayne Burdick <n6kr at elecraft.com> writes:
>
> > I set mutual attenuation to 30 dB, a rough estimate of the path loss
> > using dipoles 500' apart at 7 MHz. This is a pretty wild guess,
> > though. Loss could be much higher if the antennas were oriented to
> > avoid coupling, and it'll vary with frequency, terrain, actual
> > distance, etc. Of course path loss could be lower with gain antennas
> > at either or both ends, aimed at the other. (A situation generally
> > avoided at FD.)
>
> I think 30 dB loss is an extremely conservative test and that very few
> people will see coupling that strong.
>
> At my club's 2019 Field Day, with help from several, I made measurements
> of received signal strength at several of our stations with various
> antennas, with a nominal 100W test carrier.  Measurements are just
> reading a P3 -- and note that none of the P3 owners had paid for the
> NIST-traceable calibration certificate.
>
> Setup was CW station with K3newsyn, digital station with IC7300, only
> 20m separation from one CW antenna to the digital antenna.  And SSB
> station with K3newsyn, 200m away.
>
> We did not have trouble, but always had at least 50 kHz separation.
>
> Received levels ranged from S9+40 to S9+73, with S9+50 typical.
>
> So received signals were
>
>   -33 dBm min, -23 dBm typical, 0dBm max
>
> With +50 dBm transmit, that works out to path loss:
>    83 dB max, 73 dB typical, 50 dB min
>
> (The 0 dBm received signal was between an OCFD and a G5RV, about 20m
> apart.)
>
> It is interesting to hear of S9+65 from a neighbor.  Even if they are
> running 1.5 kW, seems like it must be only a few hundred meters
> separation.  If it's farther the details of distance, tx power, antenna
> types would be interesting.
>
> I realize this is not responsive to Eric's question about the K4, but
> thought that additional real-world cosite path loss data points would be
> of interest..
>
> 73 de n1dam
>