How do I fix a Hy-Gain Balun?
K7LXC at aol.com
K7LXC at aol.com
Sun Jul 7 13:10:12 EDT 1996
In a message dated 96-07-07 09:31:24 EDT, you write:
>Last winter, my rotor came apart and my TH-7 started
>"windmilling". This pulled coax out of the balun that
>comes with the antenna. There is a SO-239 type
>connecter in it and the threaded sleeve pulled away
>from the bottom of the connector, leaving the center
>insulator.
>The balun enclosure is made of plastic, and seems to be
>glued together. I am at a loss as how to repair
>the SO-239 without destroying the plastic enclosure.
>Has anyone had this problem with their CONTEST
>station and found a good way to fix it? If you had
>to destroy the plastic enclosure, what did you to replace it?
Hi, Tom --
You can call the factory, maybe they can help you. Linda Siverstrand
takes care of antenna parts problems (402-465-7022). If it were mine, I'd
probably go ahead and replace it. Since the Hy-Gain baluns have been known
to leak, putting it in a different enclosure probably wouldn't hurt
anything. Is it worth spending the time to fix it?
BTW, you may want to check into Towertalk, the tower and antenna
construction reflector. It has many knowledgeable people on it and is a
terrific source of information for tower and antenna questions. Send a
message to towertalk-request at akorn.net with subscribe in the message to sign
up. See you there.
73, Steve K7LXC
>From n1mm at usa.pipeline.com (Tom Wagner) Sun Jul 7 18:07:19 1996
From: n1mm at usa.pipeline.com (Tom Wagner) (Tom Wagner)
Date: Sun, 7 Jul 1996 17:07:19 GMT
Subject: How do I fix a Hy-Gain Balun?
Message-ID: <199607071707.RAA26365 at pipe5.t2.usa.pipeline.com>
Thanks to all for the replies on my query above.
Responses can be categorized as follows:
1. Replace with a 6-turn coax balun made
from 8' of coax.
2. Replace with an after-market balun,
since the Hy-Gain may not be able to
handle legal-limit under wet conditions.
3. Replace with a ferrite-bead current balun.
I'm going to do #1. Seems like the most
foolproof and happily is also the cheapest!
Thanks!
Tom
>From oo7 at astro.as.utexas.edu (Derek Wills) Sun Jul 7 18:27:41 1996
From: oo7 at astro.as.utexas.edu (Derek Wills) (Derek Wills)
Date: Sun, 7 Jul 1996 12:27:41 -0500
Subject: Kenwood VFO-230
I've already had an offer to mail relevant parts of the vfo manual,
plus advice that the TS-830 service manual covers the -230, so
this might save others telling me the same thing. If it helps,
the VFO is getting the correct freqs from the 830, but the 830 is
getting nothing from the VFO. See you all in the contest at the
weekend, so long as you aren't working split...
Derek AA5BT, G3NMX
oo7 at astro.as.utexas.edu
>From ke6ber at tiac.net (Alfred J. Frugoli, KE6BER/1) Sun Jul 7 18:45:49 1996
From: ke6ber at tiac.net (Alfred J. Frugoli, KE6BER/1) (Alfred J. Frugoli, KE6BER/1)
Date: Sun, 7 Jul 1996 13:45:49 -0400
Subject: 160M antennas and parts
Message-ID: <v01540b00ae056a1930fc@[206.119.237.36]>
I am in the planning process for a 160M contest antenna. I know that there
is much to be said for inverted L's and towers as 160 antennas. I am
currently looking at putting up either an inverted L or a 50ft top loaded
vertical. Here are my questions.
1) Are there any references out there on specific construction techniques
for coils and matching networks. (I need these components to handle
legal-limit)
2) What are the effects of having the vertical portion of an inverted L
next to a metal support (i.e. a tower).
3) Is there any antenna modeling software that will help me with figuring
radiation resistance, capacative loading, matching etc that will run on a
386 w/dos, or a Mac?
Thanks in advance, and hope to hear you on 160 this season.
Al, KE6BER/1, ke6ber at tiac.net http://www.tiac.net/users/ke6ber
>From seay at alaska.net (Del & Jan Seay) Sun Jul 7 17:54:36 1996
From: seay at alaska.net (Del & Jan Seay) (Del & Jan Seay)
Date: Sun, 07 Jul 1996 09:54:36 -0700
Subject: How do I fix a Hy-Gain Balun?
References: <199607071707.RAA26365 at pipe5.t2.usa.pipeline.com>
Message-ID: <31DFEBCC.7CD1 at alaska.net>
Tom Wagner wrote:
>
> Thanks to all for the replies on my query above.
>
> Responses can be categorized as follows:
>
> 1. Replace with a 6-turn coax balun made
> from 8' of coax.
> 2. Replace with an after-market balun,
> since the Hy-Gain may not be able to
> handle legal-limit under wet conditions.
> 3. Replace with a ferrite-bead current balun.
>
>
> I'm going to do #1. Seems like the most
> foolproof and happily is also the cheapest!
>
> Thanks!
>
> Tom
Before you take that step, check with some of the contestors on their
experiences.
The coaxial balun is a sound method - however - when you make one
for a triband beam, there is a real good chance you will find one
or more frequencies where the voltage from conductor to tconductor,
or even turn to turn will exceed the insulation ratings and cause a
short. If you run high power (kw or more), you may regret that
decision. Good luck de KL7HF
>From ke6ber at tiac.net (Alfred J. Frugoli, KE6BER/1) Sun Jul 7 19:11:48 1996
From: ke6ber at tiac.net (Alfred J. Frugoli, KE6BER/1) (Alfred J. Frugoli, KE6BER/1)
Date: Sun, 7 Jul 1996 14:11:48 -0400
Subject: Ameritron AL-80 Summary (long)
Message-ID: <v01540b01ae057259212b@[206.119.237.37]>
I would like to thank all who replied to my inquiry about the Ameritron
AL-80 amp. VE2DUB, NU1U, W7LZP, KN3C, N4TG, & AA4GA. I know I missed a
couple there. I accidentally deleted their messages. The short story is
that the AL-80 is a good amp. It has been used on generator power, and at
DX locations with good success. The single 500Z tube is probably stressed
at the amps advertised 1kw outupt during a contest. One reply that I
deleted was that the amp had been used for a 10M repeater putting out 350W
without any problems for 2 years. Sounds like for the price I'm paying I'm
getting a good amp, and something that can eventually get passed on to a
second radio when that happens here. Once again, thanks to all who
responded.
--Original Message--
Any contesters out there using the AL-80 Amp? Sounds like a descent amp
from the catalog paragraph. Curious about fan noise, etc. Please reply
direct and I'll summarize for those interested. Thanks.
--Replies--
From: MICHAEL P ROSS <mp_ross at alcor.concordia.ca>
Hi Al,
We used an AL-80 for field day this year. I picked it up used at a hamfest
and this was its first contest. We were getting around 400 watts out
but the generator voltage was a bit low. The fan noise wasn't objectionable.
It didn't get as hot as some of our club's other amps. The attraction for
field day was the single box, built in power supply and 110 Volt input
voltage. It put out enough power to justify going high power vs low power
based on some signal reports we got before the contest. I don't know how
good the tube is in ours. The power seemed to peak with very little loading.
That's about all I can tell you about the AL80, other than it was the AL80
and not the AL80 A or B that they are selling now. Will be trying a known
tube in it to check out the output power level later.
I would appreciate receiving a copy of the replies you got. Hope this helps.
73 Michael Ross VE2DUB from VE2CUA Concordia University ARC Montreal
------------------
From: "Ron Martin" <kamar at tiac.net>
Hi Alfred,
I've been using the Heathkit version of the AL-80A for the past several
years. The amp is a good workhorse with little noise. If you don't need
1500 watts but about half this, the amp is a good choice. I run mine on a
separate 120 VAC breaker; learned to do this when I keyed up everything on
the same breaker. Boy did the room go dark. I have an Heathkit
SB-221sitting on the floor that puts out about 1200 watts; don't need that
kind of power with its 240 VAC wiring.
Ron, NU1U
------------------
I'm using the Heath SB-1000 which is identical except for the front panel.
The fan is tolerable, not too bad. I've got lots of hours on it with no
trouble at all. The designer was W8JIT, Tom, who is often seen on the
various newsgroups.
73, Bill W7LZP
wrt at eskimo.com
------------------
From: Rick Markey <rpmarkey at nbn.net>
Al, I use a Heathkit SB-1000 which I'm told is a clone of the AL-80. I
love it and would love to have another one. Output is just over a KW on
most bands. Now don't get me wrong, I'd love to have one of these big
mother amps capable of 3 KW that just loafs along at legal limit, but until
I get there my SB-1000 is just fine. BTW, I've had the opportunity to play
around with a couple of Kenwood TL-922's. Wouldn't trade the SB-1000 for a
922 even if I was delirious!
de Rick, KN3C
------------------
From: ralph h young <n4tg at tricon.net>
AL I have owned an AL-80a. Mine had the internal QSK board. I have also
owned two AL-1200's, ALpha 70V and 374A, Sb-220, Dentron Clipperton L and
Henry 2K4, 3Ka and 2KD.
I am currently using a TenTec Titan.
The AL-80 worked fine and gave me no problems after I fixed two bad solder
joints, one in the input network and one in the QSK board. It's instant on
and will put out around 800 watts CW, 1000 SSB and can be run at about 500
watts on RTTY. We used one in multi-op SS CW at KI4UZ's for a few years.
The fan noise was objectionable to me, but I am rather sensitive in that
matter. It's a higher pitched noise than the louder AL-1200's (the new
AL-1200's are quiter than old ones but they are loud). The fan noise is
similar to a TT Centurion's. The quiet amps were the Sb-220, Henry 2kd and
the 70V. The loudest was the 3Ka and the 1200.
If you want an instant on amp that is pretty reliable, and don't need the
full 1500 out, it's a good value. They now have the AL-80B out that has
better metering and improved ALC. I'm not sure if they offer the internal
PIN QSK opton any more.
By the way, I bought all my amps used. You just have to be careful and
realize that some folks have a skewed version of the meaning of "mint"!
------------------
From: Lee Hiers AA4GA <aa4ga at contesting.com>
Al...
I've got a Heathkit SB-1000, which is basically the same amp. I
haven't had it online for about 2 years or so (haven't wired the 220
in the new QTH yet!), but would not consider it a serious contest
amp. The fan is not the quietest I've ever heard, but tolerable.
The problem is, you're only running about 800 watts or so output,
which is about 3db below the competition. Also, I think 800 watts
is too much to ask a 3-500Z to do on an extended basis. I generally
run mine at about 500 watts output (on CW anyway) to keep the tube
from running too hot.
It is an OK amp - for its power level. I only use it occasionally
in contests, such as when I playing around or if it is a Sprint. I
normally enter contests from somewhere else as part of a multi-op,
or if at home, I operate low power class. If I did decide to start
running high-power in the contests, I would definitely get another
amplifier that is capable of 1500 watts, and use the SB-1000 as the
amp for the second radio, where the duty cycle is less and the need
for full power is not as great.
GL & 73 de Lee
=-=-=-=-=-=-=-=-=-=-=
Lee Hiers, AA4GA
Cornelia, GA
aa4ga at contesting.com
=-=-=-=-=-=-=-=-=-=-=
------------------
That's All Folks!!!
Al, KE6BER/1, ke6ber at tiac.net http://www.tiac.net/users/ke6ber
>From garyk9gs at solaria.sol.net (Gary Schwartz) Sun Jul 7 19:31:54 1996
From: garyk9gs at solaria.sol.net (Gary Schwartz) (Gary Schwartz)
Date: Sun, 7 Jul 1996 13:31:54 -0500 (CDT)
Subject: How do I fix a Hy-Gain Balun?
Message-ID: <Pine.3.02.9607071350.A2233-b100000 at solaria.sol.net>
On Sun, 7 Jul 1996, Del & Jan Seay wrote:
>
> Before you take that step, check with some of the contestors on their
> experiences.
> The coaxial balun is a sound method - however - when you make one
> for a triband beam, there is a real good chance you will find one
> or more frequencies where the voltage from conductor to tconductor,
> or even turn to turn will exceed the insulation ratings and cause a
> short. If you run high power (kw or more), you may regret that
> decision. Good luck de KL7HF
Another thing to avoid is using foam dielectric coax. Because of the
constant bend in the coax, the foam dielectric will "cold flow" eventually
causing a short to the braid.
BN-86's make good RF fuses....changing them is a bear!
73,
Gary K9GS
__________________
/ K9GS |______________________________
/ FP/K9GS, TO5M |Society of Midwest Contesters |____________________
( | garyk9gs at solaria.sol.net |Secretary/Treasurer/
\ Gary Schwartz | K9GS at WA9KEC.WI.USA.NOAM | Greater Milwaukee/
\__________________| PacketCluster: NB9C | DX Association (
(________________________________| GMDXA \
(_____________________\
>From kl7y at alaska.net (Dan Robbins) Sun Jul 7 23:38:39 1996
From: kl7y at alaska.net (Dan Robbins) (Dan Robbins)
Date: Sun, 7 Jul 1996 14:38:39 -0800
Subject: How do I fix a Hy-Gain Balun?
Message-ID: <9607072238.AB10814 at alaska.net>
>
>Tom Wagner wrote:
>>
>> Thanks to all for the replies on my query above.
>>
>> Responses can be categorized as follows:
>>
>> 1. Replace with a 6-turn coax balun made
>> from 8' of coax.
>
>> Tom
>
>Before you take that step, check with some of the contestors on their
>experiences.
>The coaxial balun is a sound method - however - when you make one
>for a triband beam, there is a real good chance you will find one
>or more frequencies where the voltage from conductor to tconductor,
>or even turn to turn will exceed the insulation ratings and cause a
>short. If you run high power (kw or more), you may regret that
>decision. Good luck de KL7HF
>
KL7HF is correct. I had a problem with this method on a 105BA. The top of
the RF choke coil of coax was taped to underside of the boom so the choke
hung down. The shield of the coax would arc over to the boom, even with a
mere 100 w into it. Naturally the arcing was underneath the taped part, so
it was impossible to see with just a cursory inspection. I wound up taping
a 3/8" thick piece of unknown plastic on the bottom side of the boom and
using that as an insulating spacer between the boom and the coax coil. That
worked just fine. I have used coaxial choke baluns on probably a dozen
beams without any problems until I ran into this one. Interestingly enough,
the lower 105BA in the stack never had any problems although the chokes were
wound identically and made from the same roll of RG-8 (solid dielectric, not
foam). Maybe the arcing one was taped a lot tighter and squished the coax
jacket, I don't know. At least the fix was pretty easy once the problem was
found.
Dan KL7Y
>From k0wa at southwind.net (Lee Buller) Sun Jul 7 23:44:19 1996
From: k0wa at southwind.net (Lee Buller) (Lee Buller)
Date: Sun, 7 Jul 1996 17:44:19 -0500 (CDT)
Subject: DSP Boxes Summary; Part II
Message-ID: <199607072244.RAA09786 at onyx.southwind.net>
Here are some more comments I forgot to put into the original summary about
DSP Boxes. These were on my computer at home. My apologies to the senders.
I have no idea. I bought a JPS NIR-10 when it came out, and have shelled
out for ROM upgrades twice. Ver 4.0 in there now. The upgrades have
improved it, but I dunno how it stacks up to an NIR-12. The current
incarnation of the NIR-10 has simultaneous peaking and noise reduction,
with the amount of processing somewhat conrollable with an analog knob.
At times one can make CW sigs jump out of the noise; at other times not.
I have less experience with it on SSB. One cannot deploy the digital
bandpass filters simultaneous with the other functions.
I also bought a Timewave DSP-9+ when it came out. Unlike the NIR-10,
filtering and noise reduction can both be employed. One can choose a
number of CW bandpass center frequencies--but only two at a time,
according to internal jumpers. Two seems enough. It has an AGC, and
settings not only for CW and SSB, but the digital modes. However, the
fancy and much-ballyhooed RTTY remodulator is, IMHO, essentially useless
on weak signals. And I have found combinations on CW that put spurious
steady tones--akin to oscillations--into the audio output.
Before buying either of these, I had a Super SCAF switched-capacitor
bandpass filter. Currently I have all three in cascade--the Timewave
drives the NIR-10 which drives the SCAF. I utilize various
combinations. The SCAF remains useful because it reduces the
high-frequency hiss present in the TS-930S audio output, and in the
output of both DSP units. The SCAF is also able to provide very narrow
bandpasses for CW.
I have used this setup only a short time, and am still trying out
different combinations under different and difficult conditions. My
current impression is that the DSP-9+ is less than I originally thought
it was, and that the NIR-10 with the new ROMs is more than it originally
was, but that combinations appear to be more effective than any of the
units by themeselves. It does require a lot of juggling of gain controls.
In short, neither of the DSP boxes represents the millenium, and I am not
ready to give up the SCAF. And, regarding using the combination in
CONTESTS is concerned, it is generally too much effort in contest
condx, and is more suited to weak-signal, high-QRN DXing, as on the low
bands.
Garry, NI6T
I have an MFJ 784B. It does everything as advertised. But I don't use it that
much. The filters are pretty sharp. It does make marginal stations come out of
the mud on CW. I don't find the SSB portion that useful. I have used the SSTV
section. It wont make a marginal picture any better, but it will make a fair
signal pretty good. Filters out 99% of the noise then.
73,
Al - kk5zx
Regarding DSP filters: I have a MFJ-784 super DSP filter. The thing is
phenomenal- does things I can't believe. Takes out noise and leaves
signal and narrows down to almost 0 bandpass; wherein lies the problem-
for contest work it is actually too much. With filter in tuning for S & P
is almost impossible because you tune across the signals so quickly, and
when CQing the bandpass is too narrow- filters out any signal not right
in bandpass. The thing is great for tuning in a signal once you have
found it. However, once again, for contest work you dont want to take
that much time to tune him in. I love my MFJ DSP and it works great- but
the filters in my TS-940s (500khz in both IFs) are much more practicle
for contesting.
Hope there is some info in this post that may be useful.
73 de KM0L Steve in KC
I operate about 60% CW and 30% SSB and 10% RTTY. I bot the JPS NIR-10 in Dayton
in '92. Lots of hype abt it at the time. Never really liked it. Does help
reduce
HISS in the audio, but the filter action on CW was terrible, caused distortion
and popping. Bot the Timewave DSP-9+ for my mobile 6 and 2M operations. Works
well too reduce the constant hiss on the vhf/uhf bands, which helps prevent
operator fatigue during long ridge-top stints. The level of DSP action is
adjustable by pushbuttons and not continuously-variable with knobs. Afer this
posiive experience with Timewave, I then bot the more fully-configured Timewave
DSP-59+ for my IC-761 home HF station. I found the CW filters in the DSP 59+ to
be superior to my rig's 250 Hz filters in two IF's. I found the Timewave to be
especially useful on RTTY. I used the 250 Hz filter setting in addtion to both
250 Hz filters in the 761 and it made for better RTTY copy. I recently upgraded
my main station rig to the IC-775DSP. I find the overall DSP action of the
built-in DSP in the new Icom to be abt as good as the outboard boxes (the
Timewaves), but with less overall control than the DSP-59+. Some of the choices
for BW and hi/lo set points are available only through a rather convoluted menu
system on the rig, but once set, it works well. It offers both overall nose
reduction, auto notch tone removal and auto audio peak filering (very
usefull to
help dig-out those weak cw Q's).
In summary, I have found the outboard boxes to be quite useful for narrow
filtering for CW and RTTY, with marginal improvement for SSB. Although the
auto-notch function for SSB is quite worthwhile to remove tuners, hetrodynes,
etc. The auto-peak for SSB works well sometimes as well. The built-in DSP at
least in the IC-775DSP rig is easier to use and has less knobs to fool with
during contests, etc, and of course, one less box to place on the desk,
compared
to the outboard DSP units.
73, John Farber, KG6I
jfarber at sprynet.com
The last one was sent to me today 7-7-96
I hope this helps....
Lee
k0wa at southwind.net
>From n1mm at usa.pipeline.com (Tom Wagner) Mon Jul 8 02:49:14 1996
From: n1mm at usa.pipeline.com (Tom Wagner) (Tom Wagner)
Date: Mon, 8 Jul 1996 01:49:14 GMT
Subject: How do I fix a Hy-Gain Balun?
Message-ID: <199607080149.BAA17631 at pipe5.t1.usa.pipeline.com>
Whew! I can't believe the replies to my post regarding
fixing a Hy-Gain BN86 balun.
This afternoon I was able to open the top of the
balun. Just knowing that others had successfully
opened it made it easier. Here's what I did. I used
a utility knife to score the seam between the top and
the bottom of the box. (The top is the side that is
away from the boom, when mounted on the antenna.)
It's easiest to start at the coax connector end and force
the utility knife between the sections there. Alternating
sides and ultimately the end of the box, I was able to
force the glued parts apart. I used a screwdriver to
add gentle pressure once I got started on a side.
The extensions of the top that hold the balanced-side
terminals are not glued, so not to worry. Once the
top is off, the SO-239 can be removed and replaced.
You'll need to drill out the rivet holding the ground-
side connection. A standard SO-239 will fit perfectly.
So much for that. I now have a nice 1-1 balun, but it's
not going on the TH-7. I will be using an air-wound
4 1/4" diameter close-spaced on PVC coax balun for the
tribander.
WF3T was kind enough to send me his post from a while
ago on the experiments he did on coax baluns. His
definitive comments on this topic are appended below.
This is definitely required reading.
73,
Tom
>----- Forwarded message (WF3T <steve.steltzer at paonline.com>) -----<
Hi Tom,
Here's a copy of a prior post I think you will find very usefull. I
am not familiar with the BN86 balun, but if it's not a 1:1, (ie: just a
choke rather than a transformer/choke) a coax coil will not transform the
impedence to 50 ohms. If it is a 1:1, study this and you'll find you want
to
wind your balun/choke on a piece of 4" PVC. I've used his chart to make
chokes for 80 and 40 meter dipoles. Seem to work fb.
73, Steve
Here's something I wrote up a while ago on coaxial balun measurements.
It's a little long, but I think there's enough contesters out there
building these things that it's worth posting.
73,
Ed Gilbert, WA2SRQ
eyg at hpnjlc.njd.hp.com
---------------------------------------------------------------------
Having access to a Hewlett-Packard 4193A vector impedance meter at
work, I have made measurements on a number of baluns, coaxial and
otherwise. For my beams I was particularly interested how many turns
and on what diameter are optimum for air core coaxial baluns, and what
the effect of bunching the turns was (formless). Using the remote
programming capability of the HP4193A along with an instrument
controller, I measured the magnitude and phase of each balun's winding
impedance at 1 MHz intervals from 1 to 35 MHz. For comparison, I also
made measurements on a commercial balun which consists of a number of
ferrite beads slipped over a short length of coax. I've appended some
of these measurements so you can draw your own conclusions.
PVC pipe was used for coil forms. The 4-1/4 inch diameter baluns were
wound on thin-walled PVC labeled "4 inch sewer pipe". This material
makes an excellent balun form. It's very light weight and easy to
work with, and I obtained a 10 foot length at the local Home Depot for
about 3 dollars. The 6-5/8 inch diameter forms are 6 inch schedule 40
PVC pipe which is much thicker, heavier, and more expensive.
Each test choke was close-wound on a form as a single-layer solenoid
using RG-213 and taped to hold the turns in place. The lengths of
cable were cut so there was about 2 inches excess at each end. This
allowed just enough wire at the ends for connections to the HP4193A's
probe tip. After data was collected for each single-layer
configuration, the PVC form was removed, the turns were bunched
together and taped formless, and another set of measurements was
taken. I have only included the "bunched" measurements in the table
for one of the baluns, but the trend was the same in each case. When
compared to the single-layer version of the same diameter and number
of turns, the bunched baluns show a large downward shift in parallel
self-resonance frequency and poor choking reactance at the higher
frequencies.
Interpreting the Measurements
-----------------------------
All the baluns start out looking inductive at low frequencies, as
indicated by the positive phase angles. As the frequency is
increased, a point is reached where the capacitance between the
windings forms a parallel resonance with the coil's inductance. Above
this frequency, the winding reactance is reduced by this capacitance.
The interwinding capacitance increases with the number of turns and
the diameter of the turns, so "more is not always better".
The effects of a large increase in interwinding capacitance is evident
in the measurements on the balun with the bunched turns. This is
probably a result of the first and last turns of the coil being much
closer together than the single-layer coil.
An important requirement of these baluns is that the magnitude of the
winding reactance be much greater than the load impedance. In the
case of a 50 ohm balanced antenna, the balun's winding impedance is
effectively shunted across one half the 50 ohm load impedance, or 25
ohms. A reasonable critera for the balun's winding impedance for
negligible common mode current in the shield is that it be at least 20
times this, or 500 ohms. The measurements show, for example, that 6
turns 4-1/4 inches in diameter meet this criteria from 14 to 35 MHz.
The measurement data also reveals the power loss these baluns will
exhibit. Each of the measurement points can be transformed from the
polar format of the table to a parallel equivalent real and reactive
shunt impedance. The power dissipated in the balun is then the square
of the voltage across it divided by the real parallel equivalent shunt
impedance. While this calculation can be made for each measurement
point, an approximate number can be taken directly from the tables at
the parallel resonance points. At 0 degrees phase angle the magnitude
numbers are pure resistive. I didn't record the exact resonance
points, but it can be seen from the tables that the four single-layer
baluns are all above 15K ohms, while the ferrite bead balun read about
1.4K. These baluns see half the load voltage, so at 1500 watts to a
50 ohm load, the power dissipated in the coaxial baluns will be less
than 1.3 watts, and the ferrite bead balun will dissipate about 13.4
watts (neglecting possible core saturation and other non-linear
effects). These losses are certainly negligible. At 200 ohms load
impedance, the losses are under 5 watts for the coaxial baluns and
53.6 watts for the ferrite beads.
Conclusions
-----------
- A 1:1 coaxial balun with excellent choking reactance for 10 through
20 meters can be made by winding 6 turns of RG-213 on inexpensive 4
inch PVC sewer pipe.
- For 40 or 30 meters, use 12 turns of RG-213 on 4 inch PVC sewer
pipe.
- Don't bunch the turns together. Wind them as a single layer on a
form. Bunching the turns kills the choking effect at higher
frequencies.
- Don't use too many turns. For example, the HyGain manuals for my 10
and 15 meter yagis both recommend 12 turns 6 inches in diameter. At
the very least this is about 3 times as much coax as is needed, and
these dimensions actually give less than the desired choking impedance
on 10 and 15 meters.
Measurements
------------
Magnitude in ohms, phase angle in degrees, as a function of frequency
in Hz, for various baluns.
6 Turns 12 Turns 4 Turns 8 Turns 8 Turns Ferrite
4-1/4 in 4-1/4 in 6-5/8 in 6-5/8 in 6-5/8 in beads
sngl layer sngl layer sngl layer sngl layer bunched (Aztec)
---------- ---------- ---------- ---------- ---------- ----------
Frequency Mag Phase Mag Phase Mag Phase Mag Phase Mag Phase Mag
Phase
1.00E+06 26 88.1 65 89.2 26 88.3 74 89.2 94 89.3 416
78.1
2.00E+06 51 88.7 131 89.3 52 88.8 150 89.3 202 89.2 795
56.1
3.00E+06 77 88.9 200 89.4 79 89.1 232 89.3 355 88.9 1046
39.8
4.00E+06 103 89.1 273 89.5 106 89.3 324 89.4 620 88.3 1217
26.6
5.00E+06 131 89.1 356 89.4 136 89.2 436 89.3 1300 86.2 1334
14.7
6.00E+06 160 89.3 451 89.5 167 89.3 576 89.1 8530 59.9 1387
3.6
7.00E+06 190 89.4 561 89.5 201 89.4 759 89.1 2120 -81.9 1404
-5.9
8.00E+06 222 89.4 696 89.6 239 89.4 1033 88.8 1019 -85.7 1369
-15.4
9.00E+06 258 89.4 869 89.5 283 89.4 1514 87.3 681 -86.5 1295
-23.7
1.00E+07 298 89.3 1103 89.3 333 89.2 2300 83.1 518 -86.9 1210
-29.8
1.10E+07 340 89.3 1440 89.1 393 89.2 4700 73.1 418 -87.1 1123
-35.2
1.20E+07 390 89.3 1983 88.7 467 88.9 15840 -5.2 350 -87.2 1043
-39.9
1.30E+07 447 89.2 3010 87.7 556 88.3 4470 -62.6 300 -86.9 954
-42.7
1.40E+07 514 89.3 5850 85.6 675 88.3 2830 -71.6 262 -86.9 901
-45.2
1.50E+07 594 88.9 42000 44.0 834 87.5 1910 -79.9 231 -87.0 847
-48.1
1.60E+07 694 88.8 7210 -81.5 1098 86.9 1375 -84.1 203 -87.2 778
-51.8
1.70E+07 830 88.1 3250 -82.0 1651 81.8 991 -82.4 180 -86.9 684
-54.4
1.80E+07 955 86.0 2720 -76.1 1796 70.3 986 -67.2 164 -84.9 623
-45.9
1.90E+07 1203 85.4 1860 -80.1 3260 44.6 742 -71.0 145 -85.1 568
-51.2
2.00E+07 1419 85.2 1738 -83.8 3710 59.0 1123 -67.7 138 -84.5 654
-34.0
2.10E+07 1955 85.7 1368 -87.2 12940 -31.3 859 -84.3 122 -86.1 696
-49.9
2.20E+07 3010 83.9 1133 -87.8 3620 -77.5 708 -86.1 107 -85.9 631
-54.8
2.30E+07 6380 76.8 955 -88.0 2050 -83.0 613 -86.9 94 -85.5 584
-57.4
2.40E+07 15980 -29.6 807 -86.3 1440 -84.6 535 -86.3 82 -85.0 536
-58.8
2.50E+07 5230 -56.7 754 -82.2 1099 -84.1 466 -84.1 70 -84.3 485
-59.2
2.60E+07 3210 -78.9 682 -86.4 967 -83.4 467 -81.6 60 -82.7 481
-56.2
2.70E+07 2000 -84.4 578 -87.3 809 -86.5 419 -85.5 49 -81.7 463
-60.5
2.80E+07 1426 -85.6 483 -86.5 685 -87.1 364 -86.2 38 -79.6 425
-62.5
2.90E+07 1074 -85.1 383 -84.1 590 -87.3 308 -85.6 28 -75.2 387
-63.8
3.00E+07 840 -83.2 287 -75.0 508 -87.0 244 -82.1 18 -66.3 346
-64.4
3.10E+07 661 -81.7 188 -52.3 442 -85.7 174 -69.9 9 -34.3 305
-64.3
3.20E+07 484 -78.2 258 20.4 385 -83.6 155 -18.0 11 37.2 263
-63.2
3.30E+07 335 -41.4 1162 -13.5 326 -78.2 569 -0.3 21 63.6 212
-58.0
3.40E+07 607 -32.2 839 -45.9 316 -63.4 716 -57.6 32 71.4 183
-40.5
3.50E+07 705 -58.2 564 -56.3 379 -69.5 513 -72.5 46 76.0 235
-29.6
*\* steve.steltzer at paonline.com (WF3T) *\*
*\* Harley Davidson Inc. *\*
>From aa4lr at radio.org (Bill Coleman AA4LR) Mon Jul 8 03:10:04 1996
From: aa4lr at radio.org (Bill Coleman AA4LR) (Bill Coleman AA4LR)
Date: Sun, 7 Jul 1996 22:10:04 -0400
Subject: Titan Gold
Message-ID: <v01540b00ae061e226a24@[206.28.194.40]>
>I just spoke with Ten Tec yesterday about the Titan amp. They have plans to
>bring back the Titan for one last production run. TT is calling it
>Titan Gold. Price about $3375.
For that price, is it 14 or 24 carat?
<grin>
Bill Coleman, AA4LR, AA96LR Mail: aa4lr at radio.org
Quote: "Not in a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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