?Southeastern VHF Society 2025 Conference Announcement & Call For Papers
#2MAmplifier
?
Southeastern VHF Society 2025 Conference?Announcement &?Call For Papers
Quality Inn, 3095 Wilma Rudolph Blvd, Clarksville, TN 37040
April 4th and 5th, 2025
Papers and presentations are solicited on both the technical and operational?aspects of VHF, UHF and Microwave weak signal amateur radio. Somesuggested areas of interest are:
? Transmitters, Receivers, Transverters
? RF Power Amplifiers, RF Low Noise Preamplifiers
? Antennas
? Construction Projects
? Test Equipment and Station Accessories
? Station Design and Construction
? Contesting, Roving, DX-peditions
? EME, Propagation (Sporadic E, Meteor Scatter, Troposphere Ducting, etc.)
? Digital Modes, Digital Signal Processing (DSP), Software Defined Radio
??(SDR) Amateur Satellites, Amateur Television
In general papers and presentations on non-weak signal related topics such?as FM repeaters and?packet will not be accepted but exceptions may be made?if the topic is related to weak signal. For example, a paper or presentation on?the use of FM simplex in contests or on the use of APRS to track rovers?during contests would be considered.
?
Formats:
All submissions for?publication in the proceedings should be in Microsoft Word (.doc or?.docx) formats. Submissions for presentation at the conference?should be in Microsoft PowerPoint (.ppt or .pptx) format and?delivered at the conference on a USB memory stick. Please?understand that your PowerPoint Slide presentation will not be?accepted to be published in the proceedings; only meaningful text?will be published in the proceedings, not slides that need?description for understanding.
Paper: Size should be?81?2 x 11-inches.
Margins: Top and sides should be 0.75 inches; bottom must be 1?inch.
Font: You may choose your font, however, try and use standard?fonts. The font should be clean and easy to read?12 pt.
Layout: Either a one or two-column format.
Page numbers: Do not include page numbers.
Headers/Footers: Do not include Headers and/or Footers.
Drawings: Drawings should be embedded in the files. Place them?where you’d like them to appear.
Photos: Color or black-and-white digital images if utilized should be?embedded in text files. Place them where you’d like them to appear.
Printing: We print what we receive. We do not copy edit (but will?correct something if we notice it – or if you notice it and let us know).
We try to make all papers somewhat uniform, but we do not rework?each article. Page numbers are added as we prepare the files for our
printer.?
The deadline for the submission of papers and presentations?is February 15, 2025.?
Please indicate when you submit your paper?or presentation if you plan to attend the conference and present?your paper in person or if you are submitting solely for publication.
Papers and presentations are being handled by Mike Stipick,?KC4RI,?and should be sent to:?KCRI@ATT.net. Mike may be contacted at the
same email address if you have any questions.
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Re: Two tones test generator
Another way to check for linearity is to use pink noise as an input: all frequencies in the pass band simultaneously. A perfectly linear system would reproduce exactly the input spectrum as the output. The difference can be used to define the lack of linearity and its nature.?
Kim N5OP
"People that make music together cannot be enemies, at least as long as the music lasts."?-- Paul Hindemith
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On Jan 20, 2025, at 4:55?AM, Jim VE7RF via groups.io <jim.thom@...> wrote:
? Be careful when conducting 2 x tone tests.? You can easily manipulate / skew? the results by? manipulating the tone spacing.? ?Manufacturer's would do just that, years ago, to minimize IMD3 and IMD5....meanwhile higher order IMD was degraded.? That, and also manipulating the bias? to improve results.? Typ only IMD3 and IMD5 results were stated.?
My other issue with the 2 x tone test? is everything is in a steady state.? ?IE:? B+ / bias / screen voltage / fil V etc, etc...don't budge.? ?They are static, not dynamic.? ?Then toss in lousy ALC setups on some xcvr's.....which will further degrade IMD when ssb used.? The 25 ohms of DC resistance on each? grid choke in a SB-220? will result in a 3.75 V drop across each choke. (25 ohms dcr x 150 ma grid current per tube).? ?Ok, now the bias yo-yo's up/down? from 5 vdc (zener Vdc) to 8.75vdc, when driven.? That plus the instantaneous B+ will sag with full bore plate current peaks on ssb.? ?That mess will screw up the load line.?
IMO, you may be better off? with? just talking on SSB, and looking at the output on a SA (spectrum analyzer).? It's the higher order IMD products, like IMD 7-9-11-13-15-17-19? ?that cause the splatter.?
I got into it with JI, years ago,? about the tone spacing.? For his argument against ESSB he would use extreme wide tone spacings,? like 100 hz and 3200 hz on a MK-V? ( in DSP TX mode).......... or 50 hz and 5700 hz? on a modified MK-V.....(in analog mode with a pair of 6 khz filters installed).?
Try as hard as you can, but with normal speech, you can't achieve SIMULTANEOUS? lows and highs.? ? It's one or the other, but not both at the same time.? ?I tried every trick in the book, and no words, phrases will result in simultaneous highs + lows.? The only way to achieve simultaneous highs + lows is...... (A)? JI's convoluted 2 x tone tests, with extreme wide spacing.... or (B)? program material,? eg: rock and roll music fed into the xcvr.?
The 2 x audio tones fed into the xcvr will only test the xcvr.? ?With the linear amp in the circuit, the resulting IMD is no better than the xcvr.? The K3 is rated at -29db pep? (-23 dbc)? for IMD3...at 100 w pep out.? How the hell are you gonna test your L4B / SB-220? etc? ???? ?You can't.?
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Re: Two tones test generator
Be careful when conducting 2 x tone tests.? You can easily manipulate / skew? the results by? manipulating the tone spacing.? ?Manufacturer's would do just that, years ago, to minimize IMD3 and IMD5....meanwhile higher order IMD was degraded.? That, and also manipulating the bias? to improve results.? Typ only IMD3 and IMD5 results were stated.?
My other issue with the 2 x tone test? is everything is in a steady state.? ?IE:? B+ / bias / screen voltage / fil V etc, etc...don't budge.? ?They are static, not dynamic.? ?Then toss in lousy ALC setups on some xcvr's.....which will further degrade IMD when ssb used.? The 25 ohms of DC resistance on each? grid choke in a SB-220? will result in a 3.75 V drop across each choke. (25 ohms dcr x 150 ma grid current per tube).? ?Ok, now the bias yo-yo's up/down? from 5 vdc (zener Vdc) to 8.75vdc, when driven.? That plus the instantaneous B+ will sag with full bore plate current peaks on ssb.? ?That mess will screw up the load line.?
IMO, you may be better off? with? just talking on SSB, and looking at the output on a SA (spectrum analyzer).? It's the higher order IMD products, like IMD 7-9-11-13-15-17-19? ?that cause the splatter.?
I got into it with JI, years ago,? about the tone spacing.? For his argument against ESSB he would use extreme wide tone spacings,? like 100 hz and 3200 hz on a MK-V? ( in DSP TX mode).......... or 50 hz and 5700 hz? on a modified MK-V.....(in analog mode with a pair of 6 khz filters installed).?
Try as hard as you can, but with normal speech, you can't achieve SIMULTANEOUS? lows and highs.? ? It's one or the other, but not both at the same time.? ?I tried every trick in the book, and no words, phrases will result in simultaneous highs + lows.? The only way to achieve simultaneous highs + lows is...... (A)? JI's convoluted 2 x tone tests, with extreme wide spacing.... or (B)? program material,? eg: rock and roll music fed into the xcvr.?
The 2 x audio tones fed into the xcvr will only test the xcvr.? ?With the linear amp in the circuit, the resulting IMD is no better than the xcvr.? The K3 is rated at -29db pep? (-23 dbc)? for IMD3...at 100 w pep out.? How the hell are you gonna test your L4B / SB-220? etc? ???? ?You can't.?
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Re: Two tones test generator
XCVR is an abbreviation for Transceiver
MK-V is a Yaseu Transceiver
L4B is a model of an old Drake amplifier
DENON test
cds are Compact Disks for DENON test equipment
Abbreviations and model nomenclature are always going to be difficult for translation programs to figure out.
?
XCVR est une abréviation de Transceiver
MK-V est un Transceiver Yaseu
L4B est un modèle d'un ancien amplificateur Drake
Les CD de test DENON sont des disques compacts pour les équipements de test DENON
Les abréviations et la nomenclature des modèles seront toujours difficiles à comprendre pour les programmes
de traduction.
?
73,
Dave, w6de
?
?
?
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From: [email protected]
<[email protected]> On Behalf Of Fran?ois via groups.io
Sent: 19 January, 2025 06:12
To: [email protected]
Subject: Re: [ham-amplifiers] Two tones test generator
?
I would like to understand your participation but I am already very constrained by the use of abbreviations and certain words that Google does not translate
for me.
?
-
xcvr xcvr's
-
MK-V
-
L4B ?nor the hb 3x3
-
DENON test cd's
Sorry
--
F1AMM
Fran?ois
De la part de
Jim VE7RF via groups.io
贰苍惫辞测é?: dimanche 19 janvier 2025 06:58
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Re: Two tones test generator
Dimanche, 19 Janvier, 2025; 1148 EST
?
Dear Francois,
?
XCVR = Transceiver, a Transmitter and Receiver in the same box.
??????????????? Often referred to as “Tx or TX,” and? “ Rx or RX” thus: “TRX.”
?
MK-V =? The Yaesu FT-1000 Mark-5 transceiver
?
L4B = The Drake Model L4B linear Amplifier
?
“3X3” = The Eimac (or equivalent) 3 cx 3,000 ceramic tube (valve).
?
“Denon test cd’s”??? Now there you have me, Francois. I don’t know.
?
Bon Chance! et ’73,
?
Hal Mandel
W4HBM
?
?
?
?
?
?
?
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Re: Two tones test generator
Francois, I've been experimenting with a RFZero board. RFZero is an Arduino based signal generator with many, many different applications. The RFZero team has written Arduino scripts available for free download to operate the RFZero, including a two-tone generator function. The RFZero has an integrated GPS receiver so the output signal is GPS disciplined; all you have to add is an external GPS antenna & they are readily available inexpensively. The RFZero board costs ~$70 U.S. It is the basis for a project,?not?a finished product but if you enjoy building you?can make it be what you want yourself rather inexpensively.? I'm planning to use the RFZero boards as the basis for a set of propagation beacons on 10m - 70cm.? Bo, OZ2M is very supportive of the RFZero product.?
Thanks,
Robin Midgett K4IDC
Hello ? Do you have any recent experience of buying a generator of this type. Please send me references of such a product. ? Thank you -- F1AMM Fran?ois
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Re: Two tones test generator
I would like to understand your participation but I am already very constrained by the use of abbreviations and certain words that Google does not translate for me. ? ·???????? xcvr xcvr's ·???????? MK-V ·???????? L4B ?nor the hb 3x3 ·???????? DENON test cd's Sorry -- F1AMM Fran?ois De la part de Jim VE7RF via groups.io
贰苍惫辞测é?: dimanche 19 janvier 2025 06:58
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Re: Two tones test generator
U can test a xcvr? with a 2 tone....? but not a linear amplifier (the exception being if using a xcvr with Class A, like the yaesu, and even that won't work in my case, since the MK-V only puts out 75 watts in Class A, which is not enough? to drive the L4B? nor the hb 3x3).?
?
To test an amp with 2 x tones requires? 2 x separate xcvr's, each on CW cxr mode..... driving a? combiner that in turn drives the linear amp.? ?Then u can use any freq spacing you want.?
If a 2 tone? audio signal is fed to the class AB? ?XCVR....that then drives a linear amp, the IMD? from the xcvr will be a magnitude worse than the typ tube amp.?
On one of my DENON test cd's.... one of the tracks is a 2 tone, for doing IMD tests, but the 2 x tones they use? are not compatible with? typ ham gear.? (spacing too great, and out of the typ BW of a ssb xcvr).
Like Jeff sez,? just use a? 2 tone app, that drives the sound card in a PC.?
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All Electronics former employees now operate Aretronics
The former employees of All Electronics have formed a new electronic surplus store called Aretronics:?
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Re: Two tones test generator
Francois,
There are a number of 2-tone software apps that could drive a
computer sound card with very high quality output.? If you have a
computer (or laptop) near the workbench or shack, maybe that's an
easy solution.
73/jeff/ac0c
alpha-charlie-zero-charlie
On 1/17/2025 10:06 AM, Fran?ois via
groups.io wrote:
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Hello
?
Do
you have any recent experience of buying a generator of this
type. Please send me references of such a product.
?
Thank
you
--
F1AMM
Fran?ois
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Re: Two tones test generator
Thank you ? Here is one:
? Arg $140 as they humorously write: Order a couple, build both and give away one as a gift! Spread the word: Elecraft kits and accessories are now in stock at DX Engineering! De la part de Tim Duffy K3LR
贰苍惫辞测é?: vendredi 17 janvier 2025 17:13
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Re: G3SEK TRIODE BOARD on eBay
Yes. No problem.
vk6apk@...
73, Alek VK6APK.
On 18/01/2025 3:36 am, Billy Pickering
via groups.io wrote:
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Alek,
?
Can I send you an email on this? I possibly would be
interested in it, just need to talk to someone and see if we
still need it or not.
?
Thanks
?
On Wed, Jan 15, 2025 at 08:17 PM, Alek Petkovic wrote:
Yes. I bought the complete WD7S kit years ago and then
decided that it was much simpler to include the features
that I wanted in my amp constructions without the board.?
I still have it here, as I bought it, complete and unmade.
It definitely is a quality bit of gear but I don't need it.
73, Alek VK6APK.
On 16/01/2025 4:47 am, Jim VE7RF
via groups.io wrote:
For simple GG triodes,? do u really require a triode
control board ?? ?The step started HV supply, and step
started? fil supply can be done? without the triode
control board.? ?Ditto with grid and plate and cathode
overload, soft key and anything else u can think of.? ?I
looked at Ian's board eons ago, but it required a lot of
mods to work with the bigger triodes.?
The WD7S? triode board did have a unique feature.......
where if the B+ dropped below a set threshold, it kicked
the amp offline.?
That was my fear if the HV fuse I have in series with the
50 ohm glitch resistor ever opened up.? ? With no
B+....and drive applied? to any high mu? GG triode,? you
will peg the grid meter? with very very? little drive
applied.?
WD7S stated since his triode board already has grid
over current protection, his ......" B+? below a set
threshold"? ?feature is really not needed.?
I came up with my own version of grid over current
protection.......and also a newer version in the last
year... which I have not yet tested.? On paper, it should
work good.?
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Re: G3SEK TRIODE BOARD on eBay
Alek,
?
Can I send you an email on this? I possibly would be interested in it, just need to talk to someone and see if we still need it or not.
?
Thanks
?
On Wed, Jan 15, 2025 at 08:17 PM, Alek Petkovic wrote:
Yes. I bought the complete WD7S kit years ago and then decided that it was much simpler to include the features that I wanted in my amp constructions without the board.?
I still have it here, as I bought it, complete and unmade. It definitely is a quality bit of gear but I don't need it.
73, Alek VK6APK.
On 16/01/2025 4:47 am, Jim VE7RF via groups.io wrote:
For simple GG triodes,? do u really require a triode control board ?? ?The step started HV supply, and step started? fil supply can be done? without the triode control board.? ?Ditto with grid and plate and cathode overload, soft key and anything else u can think of.? ?I looked at Ian's board eons ago, but it required a lot of mods to work with the bigger triodes.?
The WD7S? triode board did have a unique feature....... where if the B+ dropped below a set threshold, it kicked the amp offline.?
That was my fear if the HV fuse I have in series with the 50 ohm glitch resistor ever opened up.? ? With no B+....and drive applied? to any high mu? GG triode,? you will peg the grid meter? with very very? little drive applied.?
WD7S stated since his triode board already has grid over current protection, his ......" B+? below a set threshold"? ?feature is really not needed.?
I came up with my own version of grid over current protection.......and also a newer version in the last year... which I have not yet tested.? On paper, it should work good.?
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Re: Two tones test generator
Bonjour Francois,
?
The last two-tone generator I purchased was
a kit from Elecraft.
?
Hal Mandel
W4HBM
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Re: Two tones test generator
Hello Francois; ? Here is one:
? 73 Tim K3LR ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Fran?ois via groups.io
Sent: Friday, January 17, 2025 11:06 AM
To: [email protected]
Subject: [ham-amplifiers] Two tones test generator? Hello ? Do you have any recent experience of buying a generator of this type. Please send me references of such a product. ? Thank you -- F1AMM Fran?ois
|
Hello ? Do you have any recent experience of buying a generator of this type. Please send me references of such a product. ? Thank you -- F1AMM Fran?ois
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Re: G3SEK TRIODE BOARD on eBay
The relay control on the GM3SEK board became messy when using tetrodes or triodes with handles.
?
There was also external parts that there were not documented? that had to be added externally for tubes like the YC156.
?
There was no easy way to regulate or protect the screen? with voltages greater than 800 volts.
?
So like most it was easier to use? your own protection circuits on? its own island connected with logic to protect the tube.
?
F1FRV has set of triode and tetrode boards that will regulate screen voltages upto 1500 volts while handling the protection and sequencing eloquently.
?
?
These boards are popular in Europe and have no rfi or other issues.
?
I came across this video that was sent to me via a link of a CB operator building? a 4cx5000.? He has his own take on the Tsunami amplifier and has some interesting ideas for protection and metering
?
?
Henry
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Re: G3SEK TRIODE BOARD on eBay
Yes. I bought the complete WD7S kit years ago and then decided
that it was much simpler to include the features that I wanted in
my amp constructions without the board.?
I still have it here, as I bought it, complete and unmade. It
definitely is a quality bit of gear but I don't need it.
73, Alek VK6APK.
On 16/01/2025 4:47 am, Jim VE7RF via
groups.io wrote:
toggle quoted message
Show quoted text
For simple GG triodes,? do u really require a triode control
board ?? ?The step started HV supply, and step started? fil
supply can be done? without the triode control board.? ?Ditto
with grid and plate and cathode overload, soft key and anything
else u can think of.? ?I looked at Ian's board eons ago, but it
required a lot of mods to work with the bigger triodes.?
The WD7S? triode board did have a unique feature....... where if
the B+ dropped below a set threshold, it kicked the amp
offline.?
That was my fear if the HV fuse I have in series with the 50 ohm
glitch resistor ever opened up.? ? With no B+....and drive
applied? to any high mu? GG triode,? you will peg the grid
meter? with very very? little drive applied.?
WD7S stated since his triode board already has grid over
current protection, his ......" B+? below a set threshold"?
?feature is really not needed.?
I came up with my own version of grid over current
protection.......and also a newer version in the last year...
which I have not yet tested.? On paper, it should work good.?
|
Re: G3SEK TRIODE BOARD on eBay
For simple GG triodes,? do u really require a triode control board ?? ?The step started HV supply, and step started? fil supply can be done? without the triode control board.? ?Ditto with grid and plate and cathode overload, soft key and anything else u can think of.? ?I looked at Ian's board eons ago, but it required a lot of mods to work with the bigger triodes.?
The WD7S? triode board did have a unique feature....... where if the B+ dropped below a set threshold, it kicked the amp offline.?
That was my fear if the HV fuse I have in series with the 50 ohm glitch resistor ever opened up.? ? With no B+....and drive applied? to any high mu? GG triode,? you will peg the grid meter? with very very? little drive applied.?
WD7S stated since his triode board already has grid over current protection, his ......" B+? below a set threshold"? ?feature is really not needed.?
I came up with my own version of grid over current protection.......and also a newer version in the last year... which I have not yet tested.? On paper, it should work good.?
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Mine are? the model..... ODC-15A? ( 15 vdc input side, and a huge plus / minus range)? ?and are rated for 250 vdc @ 1 amp on the output side.?
The other version is called a ODC-15, and output side is rated for 60 vdc @ 3 amps.?
Mine are red, and designed to be plugged into their mating board ( not needed).?
They were made by CRYDOM.....and also? Opto-22.? ?They are identical between the 2 x companies.?
They are all basically an industry standard.... and bombproof.? ? On their diagram, mine come with an internal? back emf diode built into the output side.?
I use em for keying the vac relays in the hb amps.... and also the mech relays in some of my drake amps...... and some of the drake amps now have? 3 x vac relays in em.?
Using the opto to? do the bias cutoff job? was a new one for me..... but our VK friends tell me it works superb on hb? YC-156 amps.... and any other amp. In those cases, the version with the? 60 vdc @ 3 amp? CCS output is used.?
Yrs ago, I also tried paralleling 2 x identical opto's? to handle more current....and that too also works..at least with my bench test setup, using my 0-60 vdc @ 5 amp lab supplies.??
You can also get opto's that will handle ACV on the output side.? ?I was going to try that for an experiment, used to shunt a series drop resistor for a fan cooling setup.? (Faster on TX, slower on RX, or extended RX).?
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Robin Midgett
HaL Mandel