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Bencher/Elecraft Hex Paddle Dust Cover

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Tony Martin W4FOA

Bencher/Elecraft Hex Paddle Dust Cover

Hi Gang,

I am SOOO pleased with my Bencher/Elecraft Hex paddle that I want to make sure it stays clean and pretty until I become a SK. Does anyone know of a source for a Paddle Dust Cover (plexiglass) for this jewel? I have been given a couple of references (one WB3EVL and a WP4). One source says EVL is no longer in business (an email has been sent to him) and the WP4 doesn't appear to be a satisfactory option per reviews of his work and reliability.

Appreciate any tips.

If you are in the market for a great paddle, check this one out.

72
Tony, W4FOA
Chickamauga, GA
K2 #2213

(Usual disclaimers apply)
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wayne burdick

Re: Bencher/Elecraft Hex Paddle Dust Cover

Administrator

On Feb 9, 2005, at 8:29 AM, Tony Martin W4FOA wrote:

> Hi Gang,
>
> I am SOOO pleased with my Bencher/Elecraft Hex paddle that I want to
> make sure it stays clean and pretty until I become a SK. Does anyone
> know of a source for a Paddle Dust Cover (plexiglass) for this jewel?
> I have been given a couple of references (one WB3EVL and a WP4). One
> source says EVL is no longer in business (an email has been sent to
> him) and the WP4 doesn't appear to be a satisfactory option per
> reviews of his work and reliability.

Thanks for your comments, Tony.

To the list: If anyone would like to go into business making dust
covers for this paddle, please let us know! We would definitely stock
them.

73,
Wayne
N6KR

---

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Joe Malloy

Re: Re: Bencher/Elecraft Hex Paddle Dust Cover

wayne burdick wrote:

>> Hi Gang,
>>
>> I am SOOO pleased with my Bencher/Elecraft Hex paddle that I want to
>> make sure it stays clean and pretty until I become a SK. Does anyone
>> know of a source for a Paddle Dust Cover (plexiglass) for this
>> jewel? I have been given a couple of references (one WB3EVL and a
>> WP4). One source says EVL is no longer in business (an email has
>> been sent to him) and the WP4 doesn't appear to be a satisfactory
>> option per reviews of his work and reliability.
>
>
> Thanks for your comments, Tony.
>
> To the list: If anyone would like to go into business making dust
> covers for this paddle, please let us know! We would definitely stock
> them.

And I would definitely buy one of them!

Joe, W2RBA
KX1 #0020
K1 # 1005
K2 # 1299

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Stephen W. Kercel

Keying Waveform Measurement

In reply to this post by wayne burdick

I was wondering if anyone on the reflector has tried to observe a
transmitted keying waveform using the technique described on page 25.50 of
the 2005 ARRL Handbook, and depicted in Figures 25.86 and 25.87.

The Handbook makes no mention of what the "Keying Test Generator" is or how
to correctly set it up. I'd be most grateful if someone could explain what
a "Keying Test Generator" really is.

73,

Steve Kercel
AA4AK

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Don Wilhelm-3

RE: Keying Waveform Measurement

Steve,

The setup pictured is IMHO overkill, but it covers all bases for any kind of
transmitter. No doubt the ARRL Lab has a semi-permanent setup for this
test, but all that equipment may not be required depending on what you wish
to conclude from your test

The Keying Test Generator is nothing more than a keyer - but that one has a
special output for triggering the 'scope. In most cases, the 'scope can be
triggered on the channel that the keyer output is connected to.

The setup shown requires a 'scope with a 50 ohm input to properly load the
attenuator. Commonly available 'scopes have a high impedance input rather
than a 50 ohm input. If the 'scope and probe input will accept the voltage
level presented by the transmitted signal, the attenuator may be replaced
with a dummy load (keeping the power output under the speced limit for the
'scope). In fact if all you want to look at is the shape of the output
waveform, you only need one channel connected directly to the RF output (and
a dummy load)- just trigger on the input and display 2 or 3 dot times.

If you need to measure the relative timing of the RF envelope with respect
to the keying, a dual trace 'scope is needed. Trigger the 'scope on the
channel connected to the keyer output (trigger on the negative going slope)
and you can read the delay from the onset of keying to the beginning of the
RF wavefront.

That is about all I can tell you other than those test setups shown will
work and can tell you all you need to know about the keying characteristics
of any transmitter.

73,
Don W3FPR

> -----Original Message-----
>
> I was wondering if anyone on the reflector has tried to observe a
> transmitted keying waveform using the technique described on page
> 25.50 of
> the 2005 ARRL Handbook, and depicted in Figures 25.86 and 25.87.
>
> The Handbook makes no mention of what the "Keying Test Generator"
> is or how
> to correctly set it up. I'd be most grateful if someone could
> explain what
> a "Keying Test Generator" really is.
>
> 73,
>
> Steve Kercel
> AA4AK
>
>

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Stephen W. Kercel

RE: Keying Waveform Measurement

Don:

Thanks very much. Yes, the ARRL setup is serious overkill. However, I have
a Tek 465, and I thought it would be kind of nifty to try to set it up to
look at my keyed waveform.

As for the matter of running a 50 Ohm source into a high Z scope input, Tek
has a slick solution. They use these 50-Ohm 2-Watt terminators that you
apply right at the BNC connector at the scope input. Essentially, the
source, the 50-Ohm load and the high-Z scope impedance are tied in
parallel. Of course the gotcha is that you have to use some fairly
expensive high-power attenuators to bring the transmitter output down to 2
Watts into the terminator. (The reason for running high power through
attenuators instead of simply cranking down the rig power is that the test
is intended to observe the keying waveform at full power.)

It had occurred to me that a cheaper strategy would be to run the rig into
my Heath Cantenna (remember those?) and connect a regular high-Z
compensated scope probe (the probe is good up to 100 MHz) across the dummy
load resistance. Is there some gotcha to doing that? Maybe that is not such
a good solution; 100 watts RF into a 50 Ohm load will have a voltage of
something like 200 Volts peak to peak, and I expect that that is way more
than the scope could handle. I also expect that to observe full power,
you'd need to construct a high-Z voltage divider to tie across the dummy
load, being very careful to keep its reactance low.

I also dimly recall that there was a piece in QST a few months (years?)
back describing a little sampling device (something like a directional
coupler) that you could insert in the coax line. The device was supposed to
have trivially small insertion loss, but let you look at your on-air output
on the scope direct and in real time. Any chance you remember when that
came out?

The reason the ARRL test is so fancy is that it is intended to measure
timing, the time delay between key down and the beginning of occurrence of
RF output, and the shortening of the first dot in semi-QSK schemes.

Thanks for your help with this.

73,

Steve
AA4AK

At 02:24 PM 2/9/2005 -0500, you wrote:

>Steve,
>
>The setup pictured is IMHO overkill, but it covers all bases for any kind of
>transmitter. No doubt the ARRL Lab has a semi-permanent setup for this
>test, but all that equipment may not be required depending on what you wish
>to conclude from your test
>
>The Keying Test Generator is nothing more than a keyer - but that one has a
>special output for triggering the 'scope. In most cases, the 'scope can be
>triggered on the channel that the keyer output is connected to.
>
>The setup shown requires a 'scope with a 50 ohm input to properly load the
>attenuator. Commonly available 'scopes have a high impedance input rather
>than a 50 ohm input. If the 'scope and probe input will accept the voltage
>level presented by the transmitted signal, the attenuator may be replaced
>with a dummy load (keeping the power output under the speced limit for the
>'scope). In fact if all you want to look at is the shape of the output
>waveform, you only need one channel connected directly to the RF output (and
>a dummy load)- just trigger on the input and display 2 or 3 dot times.
>
>If you need to measure the relative timing of the RF envelope with respect
>to the keying, a dual trace 'scope is needed. Trigger the 'scope on the
>channel connected to the keyer output (trigger on the negative going slope)
>and you can read the delay from the onset of keying to the beginning of the
>RF wavefront.
>
>That is about all I can tell you other than those test setups shown will
>work and can tell you all you need to know about the keying characteristics
>of any transmitter.
>
>73,
>Don W3FPR
>
>
>
> > -----Original Message-----
> >
> > I was wondering if anyone on the reflector has tried to observe a
> > transmitted keying waveform using the technique described on page
> > 25.50 of
> > the 2005 ARRL Handbook, and depicted in Figures 25.86 and 25.87.
> >
> > The Handbook makes no mention of what the "Keying Test Generator"
> > is or how
> > to correctly set it up. I'd be most grateful if someone could
> > explain what
> > a "Keying Test Generator" really is.
> >
> > 73,
> >
> > Steve Kercel
> > AA4AK
> >
> >

Roger Stein-2

RE: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

Steve,

Regarding the Heath Cantenna....I have been scratching around with power out
readings recently and after a search of the archives for the word "cantenna"
yeilded some intersting results.
What I thought over all these years (since 1964) a 50 ohm load was actually
a
68 ohm load after many years in oil and many heating cycles.
Thought that topic would be timely again here on the reflector.

Roger WA7BOC K2#755

Don:

"Thanks very much. Yes, the ARRL setup is serious overkill. However, I have
a Tek 465, and I thought it would be kind of nifty to try to set it up to
look at my keyed waveform.

As for the matter of running a 50 Ohm source into a high Z scope input, Tek
has a slick solution.......

It had occurred to me that a cheaper strategy would be to run the rig into
my Heath Cantenna (remember those?)"
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Stephen W. Kercel

RE: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

Thanks to several commentors. Looks like I need to check the resistance of
my 30-year-old cantenna.

73,

Steve
AA4AK

At 04:11 PM 2/9/2005 -0500, you wrote:

>Steve,
>
>I have no problem with my 10x probes at 100 watts and a 50 ohm load. I use
>a Tek 465 here too. But watch that Cantenna - check its actual resistance,
>they tend to climb in resistance as they age - just helped a guy out whose
>Cantenna was now a good 68 ohm dummy load.
>
>Yes, I know about those 50 ohm terminators - but as you know, they are power
>limited, and not commonly available except from Tektronics. The UHF 'scopes
>(or rather vertical plug-ins) that I have encountered have only 50 ohm
>inputs, and not many hams have those available.
>
>I didn't really say so in my post to the reflector, but if you are going to
>catch the first pulse, you will need a storage 'scope of some variety.
>Which reminds me - if you are looking at the time delay between keying and
>RF, put your 'scopes' vertical amplifiers on chop rather than alternate -
>that will assure you the keying input you are looking at does indeed produce
>the RF that is shown on the other channel. If the timing of each pulse is
>exactly the same it won't make a difference, but it is good to double check
>anyway.
>
>73,
>Don W3FPR
>
> > -----Original Message-----
> > From: [hidden email]
> > [mailto:[hidden email]]On Behalf Of Stephen W. Kercel
> > Sent: Wednesday, February 09, 2005 3:31 PM
> > To: [hidden email]
> > Subject: RE: [Elecraft] Keying Waveform Measurement
> >
> >
> > Don:
> >
> > Thanks very much. Yes, the ARRL setup is serious overkill.
> > However, I have
> > a Tek 465, and I thought it would be kind of nifty to try to set it up to
> > look at my keyed waveform.
> >
> > As for the matter of running a 50 Ohm source into a high Z scope
> > input, Tek
> > has a slick solution. They use these 50-Ohm 2-Watt terminators that you
> > apply right at the BNC connector at the scope input. Essentially, the
> > source, the 50-Ohm load and the high-Z scope impedance are tied in
> > parallel. Of course the gotcha is that you have to use some fairly
> > expensive high-power attenuators to bring the transmitter output
> > down to 2
> > Watts into the terminator. (The reason for running high power through
> > attenuators instead of simply cranking down the rig power is that
> > the test
> > is intended to observe the keying waveform at full power.)
> >
> > It had occurred to me that a cheaper strategy would be to run the
> > rig into
> > my Heath Cantenna (remember those?) and connect a regular high-Z
> > compensated scope probe (the probe is good up to 100 MHz) across
> > the dummy
> > load resistance. Is there some gotcha to doing that? Maybe that
> > is not such
> > a good solution; 100 watts RF into a 50 Ohm load will have a voltage of
> > something like 200 Volts peak to peak, and I expect that that is way more
> > than the scope could handle. I also expect that to observe full power,
> > you'd need to construct a high-Z voltage divider to tie across the dummy
> > load, being very careful to keep its reactance low.
> >
> > I also dimly recall that there was a piece in QST a few months (years?)
> > back describing a little sampling device (something like a directional
> > coupler) that you could insert in the coax line. The device was
> > supposed to
> > have trivially small insertion loss, but let you look at your
> > on-air output
> > on the scope direct and in real time. Any chance you remember when that
> > came out?
> >
> > The reason the ARRL test is so fancy is that it is intended to measure
> > timing, the time delay between key down and the beginning of
> > occurrence of
> > RF output, and the shortening of the first dot in semi-QSK schemes.
> >
> > Thanks for your help with this.
> >
> > 73,
> >
> > Steve
> > AA4AK
> >
> >
> > At 02:24 PM 2/9/2005 -0500, you wrote:
> > >Steve,
> > >
> > >The setup pictured is IMHO overkill, but it covers all bases for
> > any kind of
> > >transmitter. No doubt the ARRL Lab has a semi-permanent setup for this
> > >test, but all that equipment may not be required depending on
> > what you wish
> > >to conclude from your test
> > >
> > >The Keying Test Generator is nothing more than a keyer - but
> > that one has a
> > >special output for triggering the 'scope. In most cases, the
> > 'scope can be
> > >triggered on the channel that the keyer output is connected to.
> > >
> > >The setup shown requires a 'scope with a 50 ohm input to
> > properly load the
> > >attenuator. Commonly available 'scopes have a high impedance
> > input rather
> > >than a 50 ohm input. If the 'scope and probe input will accept
> > the voltage
> > >level presented by the transmitted signal, the attenuator may be replaced
> > >with a dummy load (keeping the power output under the speced
> > limit for the
> > >'scope). In fact if all you want to look at is the shape of the output
> > >waveform, you only need one channel connected directly to the RF
> > output (and
> > >a dummy load)- just trigger on the input and display 2 or 3 dot times.
> > >
> > >If you need to measure the relative timing of the RF envelope
> > with respect
> > >to the keying, a dual trace 'scope is needed. Trigger the 'scope on the
> > >channel connected to the keyer output (trigger on the negative
> > going slope)
> > >and you can read the delay from the onset of keying to the
> > beginning of the
> > >RF wavefront.
> > >
> > >That is about all I can tell you other than those test setups shown will
> > >work and can tell you all you need to know about the keying
> > characteristics
> > >of any transmitter.
> > >
> > >73,
> > >Don W3FPR
> > >
> > >
> > >
> > > > -----Original Message-----
> > > >
> > > > I was wondering if anyone on the reflector has tried to observe a
> > > > transmitted keying waveform using the technique described on page
> > > > 25.50 of
> > > > the 2005 ARRL Handbook, and depicted in Figures 25.86 and 25.87.
> > > >
> > > > The Handbook makes no mention of what the "Keying Test Generator"
> > > > is or how
> > > > to correctly set it up. I'd be most grateful if someone could
> > > > explain what
> > > > a "Keying Test Generator" really is.
> > > >
> > > > 73,
> > > >
> > > > Steve Kercel
> > > > AA4AK
> > > >
> > > >
> >
> >
> > _______________________________________________
> > Elecraft mailing list
> > Post to: [hidden email]
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> >
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> > Elecraft web page: http://www.elecraft.com
> >

G3VVT

Re: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

In a message dated 09/02/05 20:33:27 GMT Standard Time,
[hidden email] writes:

As for the matter of running a 50 Ohm source into a high Z scope input, Tek
has a slick solution. They use these 50-Ohm 2-Watt terminators that you
apply right at the BNC connector at the scope input

I picked up some of those with an ex military scope probe kit. Previously
used a BNC T adapter with a 75 ohm termination on the spare port for CATV
testing with a scope where a terminated line was required. A 50 ohm termination
could be used in the same way if only one has the facility to dissipate the 10
or 100W as needed.

What I did for this purpose for 2 way VHF radio testing in earlier times was
to borrow an idea from the CATV industry where close into the line
amplifier, the tap off unit from the coax feeder line (T unit) is constructed from a
resistive divider to provide the necessary attenuation. These can contain as
little as a single resistor or can be of the terminated type. For my purpose
an attenuator was made up in a small in line filter box with a straight
through connection which goes from the TX to the dummy load. Off this a resistor or
a string of resistors is arranged from the center conductor to a socket for
feeding into the test equipment. The test equipment socket was also
terminated to achieve optimum attenuation. Once the voltage level has been reduced to
reasonable levels cheaper low power coaxial attenuators can be used if
needed. The resistors have to be carbon or other non inductive types and the divide
ratio/resistor wattage can easily be work out by math. Made this up many
years ago and still have the unit today.

It is amazing what one can do with bits of junk when you have hardly two
cents to rub together!

The old UK made, KW Electronics PEP meter which can measure up to 300W
worked in a similar fashion I found years later was using a resistive divider to
bring down the voltage levels from the through RF to a level that can be used
by the metering circuit.

Bob, G3VVT
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Stephen W. Kercel

RE: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

Roger:

The topic is extremely timely. I expect there are a lot of Cantennas still
floating around out in Hamdom. One is tempted to naively treat it like a
precision 50 Ohm RF load.

I measured the DC resistance of mine with a DMM and the reading was 46.1
Ohm. I dimly recall doing some noise bridge readings at various HF ham
frequencies a few months back, and it seemed to me that the readings all
came out reasonably close to 50 Ohms. When things quiet down, I suppose I
should revisit the readings with a bit more of a critical eye.

I do not dispute than many Cantennas eventually evolve into a 68 Ohm load.

I built mine in 1977 (it is only 28 years old and not 30 as I said
earlier). I was inactive from 1983 through 2004. When I have been active it
has been mostly QRP and never above 100 W. Thus, I never really got the
puppy hot, and that may explain why the resistance is still close to 50 Ohms.

For what its worth, the resistor has been continuously immersed in oil, and
I have never changed the oil since I built the device.

BTW. Does anybody know if the reactance also tends to creep with age/use? I
cannot think of a good reason why it should, but RF properties are strange.

73,

Steve
AA4AK

At 01:10 PM 2/9/2005 -0800, you wrote:

>Steve,
>
>Regarding the Heath Cantenna....I have been scratching around with power out
>readings recently and after a search of the archives for the word "cantenna"
>yeilded some intersting results.
>What I thought over all these years (since 1964) a 50 ohm load was actually
>a
>68 ohm load after many years in oil and many heating cycles.
>Thought that topic would be timely again here on the reflector.
>
>Roger WA7BOC K2#755
>

Bob - W5BIG

Re: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

Hi Steve,

Check the spec on your scope probe. (try Google). If it can handle the
voltage at high frequencies, that is the easiest way to go. 100 watts into
50 ohms has a peak 100 volts (the peak-to-peak is 200V but the probe only
sees +/-100 volts max).

If you need to make an attenuator, it doesn't have to be compensated if you
are only interested in the shape of the waveform and not it's exact
amplitude. As long as you use linear components (no toriods), the shape of
the leading and trailing edges will be proportional to the actual waveform
and the frequency spectrum is the same. Even 50K or 100K film resistors
would work, with something around 1K to ground.

As an alternative, it doesn't take much capacitive coupling to get a usable
signal. A piece of wire near the dummy load might pick up enough signal
when your running 100 watts. In this case, a small resistor to ground can
used to control the amplitude of the signal.

73/ Bob - W5BIG

> It had occurred to me that a cheaper strategy would be to run the rig into
> my Heath Cantenna (remember those?) and connect a regular high-Z
> compensated scope probe (the probe is good up to 100 MHz) across the dummy
> load resistance. Is there some gotcha to doing that? Maybe that is not
such
> a good solution; 100 watts RF into a 50 Ohm load will have a voltage of
> something like 200 Volts peak to peak, and I expect that that is way more
> than the scope could handle. I also expect that to observe full power,
> you'd need to construct a high-Z voltage divider to tie across the dummy
> load, being very careful to keep its reactance low.
>
>

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Stephen W. Kercel

Re: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

Mark:

Yes, you're right; the 465 does have a 20 V/div max using 10:1 probes.

The lesson from you is essentially that when all else fails, read the
instructions. According to my probe manual, the probes are actually good to
500 V up to 10 MHz, then they derate to about 175 V at 30 MHz. They are
much more than adequate for observing the output of a full-featured K2.

Yes, I remember "hot carrier" FETs and the lethally high voltages required
to operate them.

73,

Steve
AA4AK

>Sheesh...these young uns! 200V P-P should be no problem for a 'scope.
>(If you look carefully, the probe is probably a 10:1 voltage divider.)
>To show 200V p-p as a full scale deflection (assuming 10 divisions
>vertically on the screen) would require 20v p-p per division. Just set
>the vertical scaling at 20v p-p/div. If you're using official Tek
>probes, you can ignore the 10:1 built into the probe because the scope
>will compensate for it automatically. If the thing doesn't have
>scalings up to 20v p-p you would need the high voltage probe set, but
>I don't remember using them for normal (non broadcast) transmitter
>service.
>
>Shouldn't be a problem -- after there are those of us who used this
>scope, (and its predecessors) to trouble shoot vacuum tube equipment.
>(Remember vacuum tubes? sometimes known as 'thermionic FETs'? They
>take high voltages!)

Stephen W. Kercel

Re: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

Bob and Bob:

Thanks to both. The advice is very useful.

73,

Steve
AA4AK

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G3VVT

Re: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

In a message dated 09/02/05 21:17:14 GMT Standard Time,
[hidden email] writes:

What I thought over all these years (since 1964) a 50 ohm load was actually
a
68 ohm load after many years in oil and many heating cycles.

----------------------

There was a report about this problem some years back in Radcom and the
answer came from no less an amateur than G5RV.

Apparently over a period of time some types of cooling oil in the Heath
Cantenna and similar types can have a chemical reaction with the carbon in the
dummy load even though it may have a protective coating. The ultimate
destruction cycle was with vegetable oil where the resistor was destroyed in as little
as one year. Frying tonight!

Bob, G3VVT
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Stephen W. Kercel

RE: Keying Waveform Measurement

In reply to this post by Stephen W. Kercel

Hi Roger:

Actually, I'm quite happy with my 46.1 Ohm reading. After 28 years of
mysterious chemical reactions, my Cantenna impedance is still well within
10% of its nominal value. I wonder if a brand new MFJ dry dummy load would
be that close.

My Cantenna also contains the Heath-recommended transformer oil. It is (was
back then anyway) readily available from commercial electrical suppliers.
(BTW, I hope yours is not using askarel; it contains PCBs. Although it was
illegal to use askarel in 1978, Heath still published performance figures
for Cantennas filled with askarel.)

Although I see no present need to overhaul my Cantenna, I'd definitely be
interested in seeing your pictures. If there is a way to post them to the
reflector, I expect that other participants would like to see them as well.

You do raise a valuable caution. Cantenna impedance values apparently range
fairly widely over the map. If people are trying to measure the power out
of a K2 (or whatever rig) by using a voltage measurement and assuming a
50+J0 load impedance, they should only do so if the measurements of the
impedance of their specific Cantenna are close to that value.

73,

Steve
Way Down East and bracing for the Nor'easter of '05
AA4AK

At 07:48 PM 2/9/2005 -0800, you wrote:

>Hi Steve,
>I have never changed the oil either, mine is actual transformer oil as my
>father worked for the local utility company as the time.
>I was having KPA100 difficulties and decided to attach the MFJ analyzer to
>the cantenna just to check it out...imagine my surprise when it read 68
>ohms. I then put the leads from my Fluke dvm on it and it read the same.
>So what I thought was 50 watts was really 36....using P = V^2/50 and in this
>case 50 was really 68.
>I have the unit apart, there is a deposit of some kind on the body of the
>resistor. One has to reverse assemble the resitor holder from the lid in
>order to get it all apart. I am going to take photos of the unit if you are
>interested in seeing what I have.
>
>I since borrowed a Bird dummy load, 51.2 ohms and a Bird wattmeter and now
>have the KPA100 & KAT100 all recalibrated as well as found one end of C5C
>not soldered!! Smooth sailing now!!
>
>73, Roger WA7BOC, way out here in Montesano, WA.
>and on the home e-mail address!
>
>-----Original Message-----
>From: [hidden email]
>[mailto:[hidden email]]On Behalf Of Stephen W. Kercel
>Sent: Wednesday, February 09, 2005 2:05 PM
>To: [hidden email]
>Subject: RE: [Elecraft] Keying Waveform Measurement
>

Leigh L. Klotz Jr WA5ZNU

Re: Keying Waveform Measurement

Administrator

On Thu, 10 Feb 2005 4:18 am, Stephen W. Kercel wrote:
> I wonder if a brand new MFJ dry dummy load would be that close.

The MFJ dummy load would probably be 51 Ohms after you take it apart and
scrape off the paint that insulates the SO239 from the case. Replacing
the brads with screws also helps.

Leigh / WA5ZNU
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