Hi Yan,
59+50 signals are not very common in contests although such signals can
sometimes be ran into. Having said that, I would avoid parking only 2 Khz
away from such a signal in the contest because they usually are pretty
clicky as well. For the record, we have remote antenna, which is 300 m away
from the main antennas. That allows us to listen on the same band where the
main signal is. At 1 Kw output the main signal on the second receiver is
just about 59+50. The isolation between antennas is about 80 db (side by
side).
KX3 also has a provision for setting IF at 8Khz which can sometimes be
pretty helpful.
73, Igor UA9CDC
----- Original Message -----
From: "XV4Y" <xv4y@nature-mekong.com>
To: <CQ-Contest@contesting.com>
Sent: Monday, June 10, 2013 7:38 AM
Subject: Re: [CQ-Contest] Busted Reversed Beacon Network spots
Bret, before you attack SDR receiver performance indiscriminately, take
a look at Rob Sherwood's review of the KX3.
Hi Pete,
You are right about the KX3.
In its detailed report, Rob NC0B specifically comments that despite its
good close DR3 the KX3 will perform badly in a contest environment.
The "digital conversion IF" is only in the vicinity of 1 KHz and image
rejection is very low (around 70dB).
The KX3 will not suffer from having its AGC pumping because of strong
adjacent signal, nor it will suffer from RMDR, but just from phantom
signals coming from the opposite band.
If you have a S9+50dB at, let's say 2 KHz below (not uncommon in a
contest), it will appear around S7 in your receiver, loud and clear.
Rob Sherwood table classification only use one index for ranking and it is
the DR3 at 2 KHz on 20m with preamp off and using a 500 Hz filter.
It was meant to compare transceiver of the 90's that were using
up-conversion circuits and thus having very good sideband and image
rejection numbers.
The KX3 is a wonderful SOTA and portable radio; not designed to be a
contest or DXpedition radio.
73,
Yan.
---
Yannick DEVOS - XV4Y
New online shop for kits and more
http://xv4y.radioclub.asia/boutique/
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