[TenTec] Re: Orion Prog AGC Threshold

[Bill Tippett <btippett@alum.mit.edu>]

W4ZV> On 10 meters it may be 2-3 uV and on 160 it will seldom be
below 20-30 uV and may reach as high as the maximum 192 uV on an
extremely noisy night (storm QRN).

S56A wrote:
This empirical data nicely ilustrates natural noise level on 160 m being
some 20 dB above higher bands and redundancy of preamps on modern <uV
sensitive radios!  It also shows low RX dynamic requirements for Top band
:-)

Referring to 160m, W8JI writes:
My local wintertime 350Hz BW noise (after amplifier) compared to a sample 
of signals on one night was:

Noise -127dBm

9H1BM -122dBm

OM0WR -95dBm

DF2PY -88dBm

WA8OLN -78dBm

W3GH -60dBm

W4ZV -32dBm

The dynamic range between noise and  W4ZV was 95dB! It also illustrates how 
important antennas, location, and propagation are rather than power. The dB 
difference between signals from the same area is profound. Many signals run 
at or near noise floor. This may not be typical of every night, but it 
shows how large the signal level variations between weak DX and strong 
signals are.

http://www.w8ji.com/receiving.htm

        Mario, it must be very nice to live in Europe where you don't have
to contend with dynamic range problems on 160!   Unfortunately that is
not the case here in the USA.  I'm also quite sure W8JI's TX signal is  ~5 dB
stronger at my QTH than I am at his since he uses a 4-square versus my
single .35wl vertical.  That would raise my dynamic range requirement to
~100 dB if I operate close to him.  Fortunately Orion doesn't  care as long
as I am about 500 Hz away.   So far, I have NEVER needed any attenuation
 to reduce IMD products  on 160, even with Orion's Preamp on.

                                73 & Happy New Year to All!

                                Bill  W4ZV

_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec