Gorge, What is the rx 4 direction delta loop you mentioned below. Thanks Fred
KB4QZH
-------- Original message --------From: GEORGE WALLNER <aa7jv@atlanticbb.net>
Date: 8/21/20 3:30 PM (GMT-05:00) To: "Richard (Rick) Karlquist"
<richard@karlquist.com>, donovanf@erols.com, Ron WV4P <wv4ptn@gmail.com> Cc:
160 <topband@contesting.com>, Mail 10 <mail10@barefoothorse.com.au> Subject:
Re: Topband: Rohn 25 Vertical questions. At C6AGU I have in-band RX on all
bands. The rigs are Flex 6000 SDR-s. On 160 m I can hear virtually unimpaired
to about 12 kHz off the TX frequency. RX antenna is 4 direction delta loop,
about 1000' from the TX vertical. The RX path includes a high performance RX
pre-amp. (The RX antenna "gain" is -32 dBi.)SDR-s can work for in-band RX, but
you must have a very "clean" RX (and TX) paths and plenty of antenna
separation. Also, lots of shielding and grounding.73,George,AA7JV/C6AGUOn Thu,
20 Aug 2020 15:17:29 -0700 "Richard (Rick) Karlquist" <richard@karlquist.com>
wrote:>>> On 8/19/2020 10:28 PM, donovanf@erols.com wrote:>> Hi Ron,>>>>>>
700-1200 foot spacing should provide good in-band receiving capability.>> SDR
receivers won't work for in-band receive, you must use a traditional>>
transceiver such as the K3, K4HD, FTdx5000, IC-7800 etc.>>>>>> Micro-arcing is
caused by transmitted RF jumping a spark gap.>> Any metal-to-metal joint that
isn't securely bonded is a candidate>> for micro-arcing.>>>>>> 73>> Frank>>
W3LPL>>> Three questions:>> 1. Does "in-band receiving" mean the same thing as
SO2R in a single> band contest? I operated a few 160 meter contests in that
mode around> 10 years ago. I used a carefully nulled receiving loop 1000 ft
from the> TX vertical.>> 2. Please explain the comment about SDR receivers not
working. I> now have a Flex 6700 that claims to be able to do full duplex.
And> that radio would not work?>> 3. If connections between R25 sections
cannot be trusted, then> how would any crank up tower possibly work as a
vertical? I have> always wondered about this.>> BTW, cellular sites have
significant problems with what they> call "passive IMD", of which micro-arcing
is a subset.>> 73> Rick N6RK> _________________> Searchable Archives:
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