Hi,
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@nando.net (k4pql) Fri Jul 26 21:45:39 1996
From: k4pql@nando.net (k4pql) (k4pql)
Subject: CW Super Check Partial D/B updated for WRTC
Message-ID: <Pine.SUN.3.91.960726163329.12147B@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@astro.as.utexas.edu (Derek Wills) Fri Jul 26 22:22:50 1996
From: oo7@astro.as.utexas.edu (Derek Wills) (Derek Wills)
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@astro.as.utexas.edu
>From ke7gh@primenet.com (Brian K. Short) Fri Jul 26 23:40:14 1996
From: ke7gh@primenet.com (Brian K. Short) (Brian K. Short)
Subject: No subject
Message-ID: <01BB7B43.8431C4A0@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.
NOTE: THE AL-1200 USES A +12V KEY RELAY. DO NOT USE THIS CIRCUIT WITH
AMPLIFIERS EMPLOYING NEGATIVE OR HIGH VOLTAGE KEYING!
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@primenet.com
>From ke7gh@primenet.com (Brian K. Short) Fri Jul 26 23:57:13 1996
From: ke7gh@primenet.com (Brian K. Short) (Brian K. Short)
Subject: The Dog Ate My Title (SORRY)
Message-ID: <01BB7B45.D034C620@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@primenet.com
>From epps@netcom.com (Charles Epps) Sat Jul 27 00:03:36 1996
From: epps@netcom.com (Charles Epps) (Charles Epps)
Subject: WRTC-96 on Television
Message-ID: <Pine.3.89.9607261653.A898-0100000@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
|