tuning r7000

Paul Fischer pff at bfs.uwm.edu
Fri Jul 26 15:37:53 EDT 1996

  I have a question regarding the tunig of an r7000 antenna. The 
problem is that the directions with the antenna claim the swr is lowest 
at two or more points on band below 17 meters. One for cw another for 
ssb. In fact, what I see on my swr meter is that they are one and the 
same. For instance, If the point of lowest swr on 20m is 14.110 on cw 
it will turn out to be the same point for ssb(as best I can tell). 
According to the directions the point of lowest swr for ssb should be 
around 14.250. Is this true? Am I just having a meter problem? It 
seems to me that resonance is resonance no matter what the mode of 
transmission is. Any thought will be appreciated. Thanks.

>From k4pql at nando.net (k4pql)  Fri Jul 26 21:45:39 1996
From: k4pql at nando.net (k4pql) (k4pql)
Date: Fri, 26 Jul 1996 16:45:39 -0400 (EDT)
Subject: CW Super Check Partial D/B updated for WRTC
Message-ID: <Pine.SUN.3.91.960726163329.12147B at bessel.nando.net>

The Super Check Partial databases for US contest calls/
DX contest calls/ or BOTH have been updated with the logs
of WRTC 1X1 stations that were made public on jzap.

The databases may be downloaded from www.webbuild.com/~k4pql

README.TXT and SCP.TXT help files are also located there.

People wishing email of the SCP's may do so by sending me
a note requesting the SCP's and enclosing your latest 
c.w. (or mixed) contest log for inclusion in the SCP's.

73, Howie K4PQL

>From oo7 at astro.as.utexas.edu (Derek Wills)  Fri Jul 26 22:22:50 1996
From: oo7 at astro.as.utexas.edu (Derek Wills) (Derek Wills)
Date: Fri, 26 Jul 1996 16:22:50 -0500
Subject: IOTA, argghh

OK, so now a few people have told me that Lundy and Wight are indeed
both EU-120, along with a bunch of other islands scattered around
the UK.  Sorry for the confusion, I'm not an IOTA devotee (but I'll
happily give FT4WE a shout).

Derek AA5BT, G3NMX
oo7 at astro.as.utexas.edu

>From ke7gh at primenet.com (Brian K. Short)  Fri Jul 26 23:40:14 1996
From: ke7gh at primenet.com (Brian K. Short) (Brian K. Short)
Date: Fri, 26 Jul 1996 22:40:14 +-100
Subject: No subject
Message-ID: <01BB7B43.8431C4A0 at ip157.phx.primenet.com>

I have recently added an Ameritron AL-1200 amplifier to my contest station
and have been using it with my Yaesu FT-990.  In the course of operation,
in CW and RTTY, I have noticed the occasional fast flashing of the HI SWR
light on the FT-990 when first keying for a transmission.  This I came to
recognize as the amplifier relay not activating as quickly as the FT-990.
Using the N6TR logging program, this was NOT the case because of the PTT
signal used by the program to prevent such timing problems.  Since I don't
always use the N6TR logging program (e.g. in RTTY mode) I became concerned
for two reasons: 1) long term effect on rig and relay, and 2) effect on
Dunestar band pass filter in line to the amplifier.

No solution appeared obvious at first.  My solid state QSK FL-7000 amp
had employed the FT-990 TX inhibit signal (INH) present on the BAND DATA
jack to interlock the amp and rig.  Alas, I thought a simple RC network
on the INH signal could disable the rig for the desired amount of time,
allowing the amplifier relay to ALWAYS completely energize before enabling
the transmitter.

What follows is a "simple" circuit for accomplishing the desired goal.
The precise time constant needed is tricky!  There are two conflicting
requirements: 1) switch slowly enough to allow the amp relay to close,
but 2) switch fast enough so that the first dit, even QRQ is not missed.
For this reason, others may want to tailor slightly the values of the
two 1k resistors in parallel comprising the R of the RC network.  These
values seem to work for me...

Again, what this circuit does is disable the FT-990 transmit signal for
a very small amount of time to allow the AL-1200 TX relay to ALWAYS key
completely, preventing the rig from very momentarily transmitting into
an open circuit as the relay closes.  It solves what I beleive some folks
refer to as the "HOT SWITCHING" problem.


FT-990 BAND DATA                                              AL-1200 AMP
----------------                                              -----------

PTT >----------------------------------------------------------+
                                  1k*          1N4001          |
INH >-----------+-----------+---/\/\/\/\---+----->|-------+----+----> PTT
                |           |              |              |
                |           |      R       |              |
                |           |              |              |
               ---          +---/\/\/\/\---+---/\/\/\/\---+
             C --- 10uf            1k*           3.3k
GND >-----------+---------------------------------------------------> GND

*NOTE: Slight adjustment of these resistors may be necessary to 
       establish the exact timing you desire.  Remember: T=RC.

Another slight problem I encountered with the AL-1200 was the occasional
open circuit of the antenna when returning to RX after a transmission.
This was obvious from the absense of noise and signals suddenly after
making a transmission.  This, I found, was a slight misalignment of the
relay contacts which I beleive I have now fixed (it has not happenned
again for some time now).

Hopefully this information will help someone else.  If not, please excuse
the bandwidth...  I would welcome any constructive comments about this
simple project.

73 de Brian ke7gh at primenet.com

>From ke7gh at primenet.com (Brian K. Short)  Fri Jul 26 23:57:13 1996
From: ke7gh at primenet.com (Brian K. Short) (Brian K. Short)
Date: Fri, 26 Jul 1996 22:57:13 +-100
Subject: The Dog Ate My Title (SORRY)
Message-ID: <01BB7B45.D034C620 at ip157.phx.primenet.com>

Somehow I lost the title of my previous post.  SORRY!

It should have been:
Non QSK Switching with FT-990/FT-1000 (long)

I really did put the title on the message, but it is Friday (of course).

AGAIN SORRY!  73 de Brian ke7gh at primenet.com

>From epps at netcom.com (Charles Epps)  Sat Jul 27 00:03:36 1996
From: epps at netcom.com (Charles Epps) (Charles Epps)
Date: Fri, 26 Jul 1996 16:03:36 -0700 (PDT)
Subject: WRTC-96 on Television
Message-ID: <Pine.3.89.9607261653.A898-0100000 at netcom14>

WJET-TV in Erie, PA, has just announced that it plans to air a 30 minute 
program about the World Radiosport Team Championship (WRTC-96) this 
coming Sunday, July 28, between 12:30 and 1:00 p.m. EDST.  A number of 
local cable companies also will carry the program, so be on the lookout 
for this broadcast if you live in Pennsylvania, Ohio, New York and 
Ontario within WJET's coverage area.

73 de Rusty, W6OAT

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