While I have not heard of any K2 gel cells leaking, it is known and I have
seen Gel Cells similar in type and size, crack and leak in UPS systems.
Especially if you have a 7 year old battery, I think I would pull it out,
even if good, and get a fresh one in there to be safe. You can always use
The Euro and Pounds Sterling are now in a very favorable position re the
U.S. dollar. Now is the time to order goods direct from USA. You pay the
VAT irregardless.
There was a news item here, a day ago, about how many British accents are
heard on the streets of New York with all the current
In my Heathkit time, they did not provide the solder, (1957). First I tried
Kester rosin core. But later, I bought Ersin Multicore, (today Multicore
Solders), upon the suggestion of some experienced ham, and it was the most
superior solder I had used. I used Kester, but did not get the
Keys almost universally would have silver contacts. Silver is one metal
whose oxide is conductive.
The contact area is a high stress point of pressure, Gold is a soft metal
and actually can develop films that inhibit good conduction, unless the
contact wipes so as to be self cleaning.
Hi Marty,
At the time I built a Heathkit DX 20 in 1957, and when several friends built
Heathkits in that era up to 1960, I don't remember any of us getting solder
with our Heathkit.
I bought Ersin Multicore solder and used that for all my kit building, and
still prefer it after some 44 years
Fred's bond paper key contact cleaning scheme is the best and most favorable
to long life of your key contacts.
-Stuart
K5KVH
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If you go to the Anderson Power Pole web site, you will find a number of
products that are used to mount multiple connectors together. The spiral
roll pin is the one most hams have heard about, but there are frames that
clamp several power poles in a cluster, and chassis mounting clamps that
When soldering APP connectors, it is important to not get oversplash of
solder outside the cup, on the outer wall of the contact, or it does not
push into the shell to the locking point. Here, we tin the inside of the
cup, and the wire end, then insert the wire end and reheat the cup to join
Binding posts (American models), are only rated at 5 Amps in standard
Laboratory 5 way size.
Properly assembled Anderson Connectors with their clip do not move around.
They are silver plated, a big plus over other available power connectors.
The contacts are self cleaning each time they are
You can reinsulate the wire by painting it with clear nail polish. In
fact, the cores are not a concern as they are an insulating material. The
bare wire touching the core is not a concern, a bare wire touching an
adjacent winding is what to avoid. You do not have to have the turns pulled
They turn off the tone modulation every hour for a bit. See their schedule
for time of this. That is the time you do your most accurate zero beating,
and in CW mode of your receiver.
Stuart
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Gil, a good technique is to make a copy of the schematic, maybe even with
magnification, to see more easily where the leads of the connector go, (to
which components). Then, with a colored pencil, trace out each pin to what
it is connected to (component), and evaluate what the reversed voltage
Was the case exposed to sun heating during the operating period? A dark
case, or any non reflective painted case, can develop quite a bit of heat
from sun exposure even in mild weather. That coupled with high duty cycle
of FD might have triggered the hi temp condition.
Stuart
K5KVH
Hi Fred,
Yes, I remember Gabriel Heater news; but the all the ships at sea was the
tag line of gossip commentator Walter Winchell. Remember him? He also had
the snappy code burst at the start of his broadcasts.
Can you believe, Andy Rooney of CBS 60 minutes was a reporter for Stars
and
Ham Com was great! The second year in the new venue with FREE parking!
(Plano Centre) (Just north of Dallas on the Central Expressway, 75. Easy
access from 75, and discount gas at the intesection.
YES, we saw, and turned knobs on the K3, which was hooked up to tune signals
on a band. A
Over many years in the RD business, I learned that there is a contractor to
do most anything in CA. You have such a base of Aerospace cos. who scramble
now for a piece of the pie, that there are contract manufacturers and board
houses to expand your production capability. The trick is to find
Brian, that is also not necessary, and the dielectric constant of an epoxy
coating might shift the resonances of the torroids.
Just wind the turns on with tension maintained as instructed in the manual.
-Stuart
K5KVH
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Brett,
There ARE kilowatt baluns, but the balun probably will not help a G5RV due
to the fact it is resonant on 20 as a gain antenna, and somewhat of a
mismatch on any other band. In fact, you would be better off running open
wire line all the way to a Tee tuner, then using a ferrite bead 1:1
Augie,
You are correct, Ham Radio went to CQ Pubs., then to ARRL, as Communications
Quarterly was incorporated into QEX.
Stuart
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The original Panadaptors, as I recall, in the WW2 era, worked in the
receiver IF, as RF spectrum analysis was but a dream when it came to
affordable circuitry.
Stuart
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Additional comments on using an A/D at the front end of a radio.
High Speed A/Ds that can handle the wide dynamic range of radio signals are
still an art form.
Any A/D suffers from the need to have filtering in front of it to avoid a
malady known as aliasing. In A/D theory, without band
This won't really buy you any advantages, and might cut down chances of
resale, since most hams don't want a modified from stock radio in more
recent models.
N connectors are most suited for outdoors or UHF applications. Or powers
much higher than Elecraft radios!
-Stuart
K5KVH
Both the half wave and 5/8 wave antennas are complete resonant structures
without the need for radials. See L. B. Cebik's web site, www.cebik.com for
his discussion modeling half wave verticals, and little was gained by
modeling radials under them.
The reflections you are concerned about are
I did not mention that obviously, one has to watch both the impedance
variation and the reactance term to use my approximation to finding the sign
of the reactance. Larry's antenna is a good exception to the performance of
simpler antennas.
Most ham antennas have well defined harmonic related
It is not too simple to measure phase with a additional circuitry. However,
it is simple to move the frequency of the antenna analyzer and see the
Reactance change, IF it is increasing with frequency it is inductive
reactance, (+); if decreasing with frequency increase, it is capacitive
Thanks Don, my work around has worked for simple antennas like dipoles,
loops, verticals, etc.
His OCF antenna has an interesting sharp resonance which must be the
principle one, but also a non harmonic resonance which is interesting. I
had not looked at a horizontal OCF (off center feed) one
I was referring to a narrowband case of examining a simple antenna to see if
it is long or short. One with well defined sharp peaks and valleys of
impedance, and one principal resonance which you can estimate from the
dipole physical length. Seems to work using my Autek or MFJ 269. I was not
Wal Mart stores abound in the South, and Orlando should have some well
equipped with fishing poles. They will be cheaper there, (less dear), than
in the dedicated fishing shops.
Stuart
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The video on tinning toroid leads, does point out the ease of doing it by
first scraping even a single bare copper spot on the lead, and then starting
the application of iron heat and solder wire there.
I had not seen this before. He used an Xacto knife blade and one swipe to
start the spot.
I have toyed with adding 160m to an existing 80 to 10m band vertical by
the simple expedient of placing an 80m trap at the top of the vertical, then
leading off a wire to make an L antenna with enough horizontal length to
load the whole on 160m.
Remember, you get nearly the efficiency of a
Jim and the group,
At every field day, our club W5KA uses 80 M Inverted Double Extended Zepp
element wire doublets.
We have had up to 250 feet of two types of window line, and with the large
Dentron tuner, we have a low loss match, and it works every signal we hear.
That is on multiple bands
How low did you have your horizontal loop? We always use a 2 wave or so one
for field day, (80m), but mostly use it on 40m and up to 15m. It is always
only 20 feet high, as that is the limit of reach of our portable ladder.
We get great signal reports, and work all over the country from the
Mike and the group,
I am currently routing heavy duty 300 ohm twin lead from a 5/8 leg 20m
antenna, thru a slot cut into some foam pipe insulation that acts as a panel
in the bottom of a aluminum sash window. The window has aluminum sill, and
frame, and individual panes of glass with aluminum
Bob,
The length of conductor from the rig chassis to the eventual ground rod,
including the length of the rod to the physical dirt, all makes a resonant
system. If such a ground lead is 1/4 wave or a substantial length at a
given band, you will have a poor RF ground.
As someone said, you need
Bob, you need quarter wave insulated radials in the shack right at the rig
ground post to eliminate the hot rf problem on each high band. Connected
at the ground rod, they do no good, since that is 18 feet ? away from the RF
source, (Rig). Also, how close is your antenna to the rig? Making
Don't worry about the carbon in the pole. It is bound up in a matrix of
plastic such that it does not make a good conductor. You can check with an
ohm meter two places say a foot apart; what does that read on your pole?
(don't break the outer covering, just hold the probe side against the
There are a number of independent probe makers. Goggle, Test Probes Inc.,
(TPI) and Probemasters.
They are carried in the electronic Distributors catalogs. Check out Newark,
Allied, Mouser, DigiKey etc.
Stuart
K5KVH
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FCC commissioners and bureau heads today are usually lawyers, not technical
types. The commissioners probably have never been technical types since
they are political appointees.
Stuart
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You could always go to a Liquor store and get some Everclear, pure spirits.
However, cleaning of the Elecraft boards is NOT necessary nor desirable.
You never know what the plastics in today's parts will do in the presence of
solvents. Use of the cut off acid brushes will work, but only as
When not in sight of the rig, as in the yard, you are probably required to
follow the FCC remote control rules. Review Part 97 before doing any remote
work.
Stuart
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Wiping the tip (clean iron tip, well tinned) before each joint is made when
doing pads and wetting the tip with the tip of the wire solder are key
steps. Touch the tip with fresh solder just before starting to solder the
joint. Apply the solder wire to the junction of the lead, pad, and iron
You should not be pushing the iron against the IC lead so hard it springs at
all.
For ICs, usually you spring the leads open a bit more than factory out of
package, and they hold themselves in the board. You spread component leads
to hold themselves into pads or hold the component with a
If you have the 1950's style Weller or Wen Soldering guns that were about
100 watts, (some were more), you can take off the tips and use the shanks to
butt up to the PL 259 type UHF inner shell, when you solder the little holes
to the shield of the coax.
You should pretin the shield where the
Frank,
You left out an important piece of information. Was the K2 plugged into an
antenna at the same time you had it on the computer and lost the MAX chip
and the components?
RS232 used to cause a lot of modem failures, because those chips make a
great fuse for lightning surges that would
Ken, I have to respectfully disagree that properly sized resistors would
mess up the tuning of the antenna and feeders.
Our radio club has operated up to 5 transmitters at Field Days, with 100,000
ohm, 2 watt carbon resistors on the 450 ohm feeders, one from each side to a
ground rod to bleed
Could this be the recent Chinese jamming signal?
Stuart
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The LED is simply a diode that glows. It is entirely possible this LED has
enough response at RF frequencies, that it is responding to your RF keying
waveform, as well as glowing with the steady DC of the supply. You might
try a clamp on ferrite choke between the Rig Runner and the rig. You
Hi antenna challenged fellow hams. You can do your own stealth gutter
antenna these days.
Two easy ways: 1) Get a combination of metal gutter and one short
section of plastic gutter to join two metal halves of a dipole. Remember,
you can use shorter than quarter wave lengths of elements,
Now this method is a bit convoluted, but you could put extra long leads on
an ohm meter that will measure low ohms. Start at the feedpoint with one
lead, and experimentally tap onto the antenna where you think the 55 foot
point is. If you have found the center, you will have the resistance
The Diamond bottom tube may, (and likely) contains a broad band ferrite
cable choke. Or there may be a combination trap/ loading coil such as used
on some tri band beams for multibands.
Stuart
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Besides upholstery shops, look at shops selling bulk cloth and sewing
supplies. Also, the various stores that spring up in larger towns selling
shipping supplies.
Down here places like U Haul not only rent trucks and trailers, but sell
packing supplies and padding.
The chain Container Stores
My NASA soldering school in the early 60's had us solder the lead first,
then trim near flush, unless it was an earth bound application, and you
would leave a bit to clip on a test lead for testing. Usually, you would
just clip flush to the top of the fillet, and use test points for testing.
One of the issues with ham equipment of recent times, is does it have a
backup battery that might be failing after 7 or more years? That is one of
the first things that comes to mind as our equipment ages.
Stuart
K5KVH
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Usually, traditional brown zip cord has one smooth insulated conductor, and
the other conductor has a rib running axially, or a series of markings to
allow one to polarize the use of the brown cord. In the old days, we made
the conductor having the rib along its entire length the neutral
If you want to splice balanced line, you can do a simple splice with two
wire nuts of both the same size.
That theoretically, would affect each side of the line the same and preserve
balance. Your tuner takes care of that and any other bumps'' even the
mixing of 300 ohm and 450 ohm line to
Canyons play havoc with verticals.
The Grand Canyon is a mile or more deep. Depending on where you are, if you
are truly in the inner gorge, you will need horizontal polarization and NVIS
mode on 40m and lower.
Of course, if you were to camp part way down on the plateau, you might be
able to
If one is building an antenna for an EOC you do NOT want to use too small a
wire, and its attendant weak breaking strength.
Use no. 14 or larger wire, stranded. Use heavier duty insulators, good
ceramics or glass if you can get them in place of plastics which deteriorate
in the sun in a short
For an EOC operation, you want an omni direction of coverage. Put a usual
antenna height, and end fed 270 foot wire on 40 m or even 80, is going to be
getting to be directional toward the far end of the wire.
MUCH better for EOC use is to put up such a wire as a center fed doublet.
Then it
I would be concerned about impedance mismatch caused by paralleling two low
impedance sources.
That would lead to degraded performance. What is so difficult about
providing a single pole, double throw switch to swap one BNC between the two
outputs? Or just mounting two BNC's? There are very
I don't think you need worry at 12 volts supply, either will work. The A
suffix is just graded out to stand higher voltages than the .
Stuart Rohre
K5KVH
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Looking at the A suffix , it appears they are graded units having a
higher breakdown voltage across the elements. It should work anywhere a
without suffix is specified.
The PN should work in PN A circuits that do not exceed its element
voltage ratings, which if you are
Most of the older meters were OK on the X100 Resistance scales. Two things
you watch out for, a few VOMs used a higher voltage on some Resistance
scales, and some used high current on low Resistance scales. Spend a little
time with the schematic for your test equipment, and you will be OK.
All field days start on GMT, ie at 1800 Z Sat., or local 1 PM Central Time
zone. They all end at 1800Z Sun.
The only exception has been if you do not start set up until 1800Z, you can
operate extra time on Sun. after 1800Z. But NO one is heard on doing that,
the bands have a huge vacuum at
actually, the two major international QRP groups, QRP ARCI and GQRP use 10
watts for SSB, and 5 watts for CW, since they are equivalent in talk
power.
It is the ARRL who is the odd man out, as most local QRP clubs follow QRP
ARCI in North America, and G-QRP in the rest of the world!
Stuart
Keith, the absolute all around easy, and works every time, antenna is the
simple balanced dipole; a half wave long for the band in use. You can use a
tuner with it and ladder line or TV twin lead feeder on higher bands.
The other simple portable antenna is the loaded ground plane. You can do
I have had all three leading consumer brands of alkaline batteries leak, and
several of the industrial size we use at work. The enemies of all alkaline
cells are heat and moisture, and time.
A number of all types of alkaline cells have reversed polarity in a string
of series cells, usually
The whole concept of radials is to improve the conductivity path for return
current to the base of the vertical antenna, when the antenna is not a
complete half wave dipole, (and therefore, balanced and a complete radiator
unto itself). You are replacing always lossy (to some degree), earth or
Good points Ron.
I usually call those RF control radials, an RF counterpoise, as sometimes
you can use one cut for each band of concern and run it around the baseboard
of a shack.
I like to think of a radial as an outside wire, and counterpoise as an
insulated inside the shack RF control aid.
A scope can be used with a demodulator, (detector) probe to bring the RF
signal and modulation into the audio range of the scope.
Sometimes you do not need perfect triggering on the RF; but it is sufficient
to see the amplitude envelope to tell if you have about the right amount of
RF voltage
Mike, in radar as in QRP, there is no free lunch.
Rest assured any broad spectrum signal can be found. For one thing it
inevitably brings up the noise floor and that can be detected. Good
receivers like the K2, could be helpful in noting such effects from new
radars or BPL use in an area.
One can dress the excess feeder over bushes, low tree limbs or most any
other support method to take up the excess feeder, if you do not want to cut
it.
However, cutting will in no way create a problem if later you need the cut
off length restored. You simply solder, or twist the ends, put a
Alex,
The 8709 was probably another in their line of surveillance receivers. It
has Wide IF filter, so is not as selective and good in crowded bands as a
K2.
There are few receivers in the world that beat the K2 specs, if any.
The WJ is a fine commercial EMC or military type receiver for its
Alex,
Have you read the reviews of it on eham and the companion full rack width
radio? There is a chance of blowing the front end, as these were used in
listening posts, not near transmitters.
Another reviewer mentioned the back up battery being prone to leaking and
has posted the
Transistor substitution: If there is at least one good junction in the
device you want to replace; you measure the diode potential of that junction
to see if you have a silicon or germanium device: 0.3 volts is typical for
Germanium, perhaps a bit less.
0.6 volts is a Silicon junction.
Now
Another classic way of using coax braid, is to push the braid back up the
central conductor, after removing the outer vinyl jacket. Once you bunch
the braid, it spreads out and you can use a sharp pointed tool to make a
hole by spreading the crossed strands. Using the pointed tool or a hook
You need to use a tuner between your antenna and the radio to avoid the
radio cutting back power to protect itself from high SWR.
You might want to try measurements without the unknown balun. They might
be better! Don't get hung up on the need for balun without trying without
first. I did
My 49 years of antenna useage has taught me it is bad to bring the high
voltage end of the antenna down close to the earth because of ground losses
due to the capacity of the antenna to earth. Not to mention the high RF
voltage induced into the shack.
My center fed antennas have all worked
Keith, on the Force 12 verticals, which are true half wave (loaded)
verticals:
They provide a feedline support for about 18 inches or so out from the
center. After that, the coax can simply go to earth to the rig, or be
supported for a greater distance. Does not make that much difference in
For Fred's antenna need:
I would investigate the Force 12 vertical antennas. I have used several of
the Sigma 5 model, (20 to 10) on science projects and they are durable, easy
to set up and take down, and work with high efficiency, equal or better to,
a dipole of full size. They are bar
I know Fred, that the Sommer beam uses some cleaver loading techniques to
give multi band performance. I think he used the same loading on his
vertical element.
Stuart
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Yes, in theory any vertical half wave that is center fed should have the
feeder run at exactly a right angle, but in practice, Force 12 provides a
support arm for the coax, and that is sufficient to bring the coax off a
couple of feet where it then can hang either parallel or at an angle to the
Well Vic, details, details, I meant that the beads do help in the near
center area, as they are quite long, as good bead chokes are.
Yes, outside the bead area, you should bring the line off as orthogonal as
you can; but in practice, the angular droop of the coax has not caused one
bit of
Take a look at the Ten Tec Vee beam, then remember that a non terminated Vee
beam is bi directional, so you do not need the termination resistors. Make
it up as a one support sloping vee as long as will fit your lot with the
angles suggested, 45 degrees. You can stake out the lower ends with
The problem could well be the age of your battery and its aging rise in
internal impedance. If it will not charge to 13 plus volts of a fully
charged battery, it indicates excessive internal resistance/ age.
The fact everything cleared up on an AC to DC supply supports the battery as
a
Not when there are such fine QRP capable meter kits out there. For a lot
less bucks.
Stuart
K5KVH
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With all the metal close to practical antennas, it is much more difficult
than automobile mobile. It is the restriction on height and width of the
antennas compared to train size.
You may do best with low dipole and be content with NVIS technique.
(Contacts out to 800 miles are possible). DX
Roy, I hate to mention the obvious, but I have never had RF in the shack
with balanced antennas and good feedlines, ie no problem with jumpers, etc.
Usually RF in the shack has a cause. Some cable is nearing quarter wave;
the mike connector is loose and not grounding. The power leads to rig
If the center conductor and shield are shorted at the rig, ONLY the shield
has any effect, and velocity factor does not enter into the action of this
type of counterpoise.
There is another type using coax, where a capacitor shorts the shield and
braid for RF purposes, (0.001 mf ceramic disc
Early in K2 history, a number of builders found spurs that would go away if
the probe was unplugged and stowed.
Stuart
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Typically, the extra bands can be a tolerance band of silver or gold. 10
per cent for silver and 5 per cent for gold. On resistors that have a
fourth color band, that sometimes is a voltage rating, if not a silver or
gold band.
Stuart
K5KVH
Actually, WWV and WWVB are not worldwide in range. Military uses a system
that is space based so they can see 12 satellites for a fix from anywhere
on the globe they may need position.
But, there are effects to GPS signals if you are not using a 12 satellite
solution, and thus, GPS quality at
Ah yes the kitoon. Had heard of it but forgotten. Seared in my memory
instead was two Field Day attempts by my club at balloon antennas, both
ending in blow overs. Much overrated as an antenna support.
Most balloons of the WX type cannot lift no. 12 antenna wire of a big
antenna, or lift it
The problem with balloon lofted antennas is you cannot often have the
balloons only go straight up. Much more likely to blow over sideways above
the location and get above neighbors, etc. More likely to get into power
lines. Late afternoons, most places have winds come up that play havoc
But, Phil,
The homeowners association SURELY could not prevent you from using the
mobile bug catcher on your car to be the antenna of your home station?
73,
Stuart
K5KVH
I have actually heard of a ham who runs a coax out under his garage door
when he wants to operate.
Hee, hee. Bet you did not expect someone to report they had experience with
underwater antennas, but I have been on an experimental project to put the
Rogers FLEX Folded Conical Helical HF antenna on a submerged vessel.
(Written up in IEEE Transactions on Antennas and Propagation)
Of course,
Indeed. Irrespective of PRB 1, FCC has separately ruled AGAINST homeowner
associations in that they cannot legislate to prevent you having an outdoor
TV antenna. A little thing called freedom of speech and press. Put up a
vertical with a dummy (or real) TV antenna atop it. Might broadband
A more effective antenna is to attach needed length to the ends of ridge
vent and run them at right angles to it down the gable. Paint to hide them
or tuck under edge of non metallic shingles.
Thus you create a Z antenna.
Note many ridge vents today are plastic, so this might not work unless
What you are seeking rather than an earth ground, is to tie the commons of
the equipment you are working upon, and yourself, suitably protected by the
wrist strap internal resistor, to the same point, and thus voltage
potential. You are trying to have everything at the same potential before
Indeed, some house grounds have induced voltages in having long runs back to
any ground point; and might not be the safest thing to tie your static mat
to as a ground point. Ground in AC systems may have imbalance phase
currents and be much different from a zero voltage point. It shouldn't
Super Glue should be fine. Some epoxies however, have fillers in them and
might NOT be passive to the RF specs of the core.
I saw this happen while working in the EMC field. We were testing a
transformer for a customer that had to attenuate RF passage thru its core
and windings. It was a
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