Hello,
The sale of my K2 fell thru so I wanted to list it once more with an added
incentive: Included in the sale is an Icom IC-2100H mobile 2meter rig still
new in the box. Thanks for looking.
Well, after years of owning my own business and having little time for
operating and less for buil
Glad to hear it Terry!
The in-process tests are great. They catch errors while it's still
relatively easy to find them!
Resoldering has fixed a lot of funny issues for many builders. While you
don't want large blobs of solder on the pads, a decent amount that has
obviously flowed onto the lead i
Thanks Ron, problem solved.
I checked U9 Pin 7 and found 13.35 vdc.
Found no shorts around the headphone jack.
Checked orientation of C32 and C33, OK.
Checked U10 pin 4 and fournd 7.94 vdc.
I reheated all solder joints on chips and jacks.
I think the problem might have been a solder joint o
Yes, that is true - the laws of reciprocity apply, and a conjugate match is
indicated here - but OTOH, the MFJ259 does not display the sign of the
reactance directly, one must check above and below the frequency of interest
to determine the sign - some other analyzers do display the sign of the
rea
James,
The KNB1 electrical design has not changed between board revisions C and D -
only the board silkscreening and perhaps a few minor PC traces would have
changed. The board changes have addressed the C6, C8 situation - otherwise
they should be electrically the same (compare the schematics).
If the L-net brings the system to resonance (X=0) then whatever reactance
the L-net introduces must be equal to the reactance present at the antenna
but opposite in sign!
For example, if the antenna shows j-500 ohms, the L-net must show j+500
ohms. So if you want to know what the antenna shows ba
I am the proud builder/owner/operator of K1/4 #2319. Had it fired up and on the
air this past weekend. Great little rig. I was building the K1NB board
tonight, and noticed the manual has directions for Rev C and Rev D. The
instructions for Rev C include installing a cap in a mis-named locatio
Don Wilhelm wrote:
Jack,
Yes, connecting a measureing instrument directly to an antenna can be
troublesome if there are strong broadcast stations in the area or other
sources of signals that can fool the instrument.
Zack Lau addressed that situation in a Technical Correspondence article in
QST
Yes, that's the basis of the N2PK VNA and it is worth looking at in a
modified version, with I and Q detection.
The new DDS chips have simultaneous I & Q outputs, which makes that part
of the design easier (N2PK design uses two AD9851's to generate
quadrature output.) The newer chips are, howe
is this an application where a direct conversion (QSD) might work better?
certainly easy to hit a narrow bandwidth.
jim ab3cv
- Original Message -
From: "Jack Smith" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Cc: "Elecraft reflector"
Sent: Wednesday, March 14, 2007 6:14 PM
Subject: Re
Don:
I have little or no problem putting an HP8752B VNA on my antenna
feedline, or my N2PK VNA. Both have narrow band receive (adjustable down
to 10 Hz in the 8752B) and hit the antenna with a reasonably hefty
signal, 0 dBm or so. Consequently, unless you have a very strong signal
inbound, me
I have had an Autek Research RF1 for many years and
been pleased with it. I do wish the on/off switch was
such that it could not be turned on by accident. I
solved that by cutting a thin piece of wood with holes
for the switches and attached it to the unit with a
rubber band. Fits in pocket and eas
Jack,
Yes, connecting a measureing instrument directly to an antenna can be
troublesome if there are strong broadcast stations in the area or other
sources of signals that can fool the instrument.
Zack Lau addressed that situation in a Technical Correspondence article in
QST a while ago - his ans
After thinking on it more, 30 KHz bandwidth is too wide to be useful for
a noise bridge detector, as it will not provide enough frequency
resolution for the lower bands. 7-7.3 MHz would only have 10 discrete
measurement points, for example.
If the device were to be used only to measure compone
Don:
My thought was a single conversion receiver with a high IF (45 MHz) with
a monolythic crystal filter, and an AD8307 as the IF amp and detector.
Use an NE602 or 612 oscillator/mixer. Throw in a 30 MHz LP filter to
knock down images. Local oscillator runs 45-75 MHz.
These filters are abo
Hello,
I'm available again to start another Elecraft kit ... either a new
kit, or one you might have already started and perhaps had second
thoughts or didn't have the time to finish.
I also do repair and tuneups.
You've probably seen me on the Builder-for-Hire site
http://www.elecraft.com/k2
For sale: K2, s/n 5494 with a KSB2, KIO2 and a KNB2
with KPA100 amp/KAT100 tuner in the EC2 case.
Professionally built and works perfectly and like new.
All manuals, cables and the extra cover for the EC2
are included. Pictures on request. $1300 shipped
conus. Please email off Reflector.
73,
Mar
and the really cool thing about the 8307 is that it only draws 7.5ma and can
work with a single lithium cell.
a cr123 is good for about 1500maH. that would allow the 8307 to work for
about 200hrs.
pretty amazing.
73
jim ab3cv
___
Elecraft mailing l
Paul,
In the fishing stores this is called a "Crappie Pole". It has nothing to do
with Sir John Crapper, it is a breed of fish. You can find it in most fishing
stores. In Orlando there is a "Bass Pro Shop" which should have them.
Cabella's is the source that I often use but I don't see one liste
Jack,
How about putting a sharp tuned circuit between the detector output from the
bridge and the AD8307 - a single parallel tuned circuit with a variable cap
and a winding on a toroid can serve with high Q over a wide frequency range
(depending on the variable capacitor size) - not much different
Since you can change the frequency and can hear something, the places to
look are the AF Amp, U9 and sidetone source Q5/U10B.
I'd start at the AF amplifier and make sure +12 is present at pin 7.
If so, next I'd take a close look at the soldering. Did you miss a pin? Is
there a short? A common p
Don:
I've been giving the subject a bit of thought as well and a noise
bridge came to mind rather quickly. I have an old MFJ 202 noise bridge I
bought 25 years ago.
However, I believe a broad band detector such as the AD8307 will fail.
The null condition is rather narrow frequency wise, and
Those who have both an Elecraft N-Gen and a KX1 have everything needed
except the bridge elements to construct and use a relatively compact version
of that Improved Noise Bridge described by John Grebenkemper in that August
1989 QST article.
The N-gen is the noise source and the KX1 can serve as t
Dave G3YMC wrote:
I would also make a plug for a noise bridge. I built the one by KI6WX
which appeared in QST in August 1989 (available to download from the
ARRL site). If you have a suitable portable rig to couple to it does
most of what the fancy analysers can do at a fraction of the cost.
I
Thanks for the reply Ron,
I also tried a set of iPod earbuds with the same results.
Terry VA6MAC
-Original Message-
From: Ron D'Eau Claire [mailto:[EMAIL PROTECTED]
Sent: Wednesday, March 14, 2007 10:09 AM
To: McMillan, Terry; elecraft@mailman.qth.net
Subject: RE: [Elecraft] K2: st L
I have an Autek VA-1 and a miniVNA and here are some tips:
1. Get an Optek neoprene camera case and store it in there. Put the
battery in the external pocket, as it gets turned on easily. Put a BNC
adapter in the battery case. I velcro-clipped the case to my antenna
bag.
2. Don't twist the c
>
> The Tenna Dipper looks too good to pass up.
It's a nice little unit - I have one, too. The thing to realize is that
it is designed to match a 50 ohm resistive load, *and nothing else*.
Your Hustler is not that - no vertical is.
(BTW, I'm curious about the 17m addition you got - I have a
The 259 is a fine unit. When I tuned up my Hustler, I borrowed one from
a local ham, rather than buying one. I also borrowed one of the little
Autek VA1 units, and I used them both. They got about the same results. I like
the 259's knobs and such better than the Autek, but the Autek gave
slightly m
It's subjective, of course, but something isn't right. I can hear the tone
in the phones (and speaker) at St L 001. I have mine set at 024. It's
downright uncomfortable at much over 100.
Do you have any other phones you can try before assuming the rig has a
problem?
Ron AC7AC
-Original Mess
"The MFJ uses up batteries, lots of AA cells."
My battery set has been in mine for several years, so this isn't
an issue for me. It does shut off automatically if one forgets.
"It's also a pain to change them (lots of screws)."
My '259B has (just) two screws holding the b
Good Morning everyone,
When doing the "Audio Amplifier and Tone Generator Test" how loud should
the side tone be. Use a pair of Sony portable headphones I can't hear
anything until I'm well into 150+, even at max volume of 200+ it is very
quiet.
Do I have a problem somewhere?
Terry McMilla
Dan KB6NU wrote:
You all might want to take a look at the Autek Research
(www.autekresearch.com) antenna analyzers.
I have an Autek VA-1 (the slightly more expensive model that displays
the sign of the reactance), an MFJ259B, and a Micro-908.
All of them must be used with great care around
Just made my first QSO, TX to CO, with K0YO and
another KX1.
New rig, first QSO with another KX1 and an old friend,
it doesn't get much better than that.
72, Bob KI0G
Finding fabulous fares is fun.
Let Yaho
The N2PK is an awesome piece of gear for the money. I have several
friends with them. I also have one sitting in a box waiting to be built.
That project got scuttled when Jack, K8ZOA found a couple of surplus HP
VNAs that we both bought. He already had his N2PK built, and another HP
as well, bu
That's true for simple series resonant antennas, Keith. But as I found
out when writing the sign detection algorithm for the LP-100, it's not
always the case. Your point is well taken, though. Small, simple, accurate.
73,
Larry N8LP
Darwin, Keith wrote:
Sign of the phase angle can be determ
Larry,
A kit is a great idea! Avoid temptations for an instrument that tries to do
everything and ends up doing many things poorly.
I had hopes that the AMQRP Micro908 kit would be a better replacement for my
MFJ259, but alas, it is very inaccurate for impedances that vary much from
50 ohms resi
There was a nice thread on this same topic, some three months ago, on
the Buddipole reflector. As a result of that discussion, in the end
I went with the AmQRP AA-908. The kit was easy to assemble,
notwithstanding that it was my first experience with surface mount
components. The price w
Sign of the phase angle can be determined by varying freq. and watching
the magnitude to up or down. I can live without the sign.
Something smaller that gives the same SWR / Impedance answers would be a
big improvement!
You go Larry!
- Keith N1AS -
- K2 5411.ssb.100 -
-Original Message---
I have the MFJ, Autek Vector Analyst and AEA CIA. Without question the
most accurate is the AEA, but I usually grab the Autek because of its
size. It also resolves sign of X. The tuning is touchy though, and the
menus are a hassle. I hadn't thought of an antenna analyzer product,
since the fiel
I would definitely second that!
Seems like every time I fish out my MFJ259B to use outdoors, something
else isn't working correctly on it
73 Dave G3VGR
K2 #4783
Stephen wrote:
Tom,
For a moment I was getting excited because I thought Elecraft had
introduced an Antenna Analyser kit! Now
You all might want to take a look at the Autek Research
(www.autekresearch.com) antenna analyzers. The basic model is only
$140, while the more full-featured model that can do things like
inductance, capacitance, and phase angle measurements is still only
$200. Neither has an analog meter,
Tom,
For a moment I was getting excited because I thought Elecraft had
introduced an Antenna Analyser kit! Now that would be a useful addition to
their product line.
Regards,
Steve
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of KJ3D
Sent: Wed
Yes, we need something better. I have the MFJ and it has been "fine".
I use it to save wear & tear on my knees. Take the MFJ to the antenna
and do the adjustment.
But, I wish the MFJ was smaller. It does far more than I need. I just
want to know the SWR at each freq. and sometimes the actual c
I have a MFJ259B. Had to hold my nose to shell out the $250 or so for
something with that build quality and design flaws (size, battery system,
etc). That said, next to my transceiver, it is the piece of equipment I use
most often and it does do the job intended. I would feel naked without it.
Hello all, I have ordered a basic K2 (to start with),
and thought I would introduce myself.
My name is Brett, the call is N2DTS, been a ham since sometime
in the 70's self educated in electronics and ham radio.
When I started out, I went right to the general ticket, and my
first rig was a Hea
I just got one. It works great. Already saved me hundreds of trips between the
shack and the antenna. I didn't want to spend the money, but there is really no
other easy way to tune an antenna. I have heard that MFJ quality has improved
in general, but can only say my unit seems fine.
73,
Tom
I blew the front end while tuning an antenna near another that was energised.
David
G3UNA
>
> From: "Dave Sergeant" <[EMAIL PROTECTED]>
> Date: 2007/03/14 Wed AM 10:04:57 GMT
> To: elecraft@mailman.qth.net
> Subject: [Elecraft] Re: MFJ259
>
> I don't have a 259 myself but some of my friends do.
Don't have experience of the psu, but a friend built the amplifier quite
easily. He had some problems with low mains supply at another friend's QTH,
but it worked fine from his home QTH. I run the heaters of another Linear Amp
from separate stab supply. The case is all steel making it robust b
I don't have a 259 myself but some of my friends do. It is clearly a
useful bit of kit.
But I have repaired a couple! I agree about the build standard, not
that hot, and not made easy to repair either with most of the
components inaccessible underneath the board. In both cases they had
been da
I have a couple of queries that some UK members may be able to help me with
!!
I have seen on the web a 20amp Watson Power-mite switch-mode PSU available
in the UK. This looks a great size for use with my K2 on my travels, I just
wonder if anyone has used one with the K2 and if they have any comme
Hi
VK5JST Aerial Analyzer, covers up to 30MHz, a kit is abt $100.
take a look at: http://www.users.on.net/~endsodds/analsr.htm
73, Matti
--
Marteinn SverrissonTF3MA
Langitangi 2Internet: tf3ma [at] raunvis [dot] hi [dot] is
270 Mosfellsbær http://www.raunvis.hi.i
Tom,
>>Any thoughts about the 259B?
Check out the following site and look at the projects link. The SCARC sell a
Antenna Analyser kit ($140AUS including international postage, which will be
not much over $100US)
http://www.scarc.org.au/
I have built one of these and it works FB. It is not of th
I have both models of the 259 and the AEA analyser. The latter is a
wonderful toy and great for filters, but not easy to use in the field on
antennas, I think because the data transfer rate is so slow and the screen
is not easy to see. The 259s are very good for tweeking antennas, though,
pr
Hi Tom,
Have a look at this site
http://www.miniradiosolutions.com/
73
Stewart G3RXQ
On Tue, 13 Mar 2007 20:23:25 -0400, KJ3D wrote:
> Hello Group,
>
> I purchased a 17 m add-on to a Hustler 6-BTV vertical and the instructions
> recommended I use an antenna analyzer to tune it up.
>
> Having n
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