I may do this again Wayne as this has sparked and interest for me. A
project of this type makes one appreciate the workmanship and engineering
that goes into some of the old radios that tracked so well. Frequency
counters are wonderful pieces of equipment but when you throw the switch on
a 100KC
I was able to get another tuning capacitor to work pretty close to the
desired 1-500KC span once on the linier dial by making the tuning capacitor
as a small part of the total capacitance of the circuit and by placing the
tuning capacitor across only a portion of the coil and the larger part of
the
Try this
http://amfone.net/Amforum/index.php?topic=4837.0
John Coleman, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Rick Brashear
Sent: Sunday, March 11, 2007 8:25 PM
To: 'Discussion of AM Radio in the Amateur Service'
Subject: RE: [AMRadio]
Jack:
I really think you should consider the solid state rectifier option
for at least the other two diodes and go bridge with the XFMR. That you
have.
John
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling
Sent: Tuesday, Decembe
"Alternate spectrum from 3585 - 3600."
Does this mean that we keep the 3600 and up for voice?
Is the FCC saying these digital guys need to just move down?
I have a lot of mixed emotions about the code exam being gone.
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto
Well then that proves that the movement is indeed a 1ma movement.
Now you need to remove the 500K ohm if you are going to be using it with an
external 5Meg else you will be 10 percent off in measurments. You could
also leave the 500K inside, and replace the external 5 meg with a 4.5 meg.
I ran a pair if 304tls in push pull. I think the bias was around 500 volts
and the grid current was around 150ma. I drove it with a pair of 812s in
push pull at about 110 watts drive. The plate supply on the 304s was around
1600 volts and the plate current was 600ma. Output power was 790 watts.
EMAIL PROTECTED] On Behalf Of John
> Coleman ARS WA5BXO
> Sent: Saturday, December 02, 2006 8:41 PM
> To: 'Discussion of AM Radio in the Amateur Service'
> Cc: [EMAIL PROTECTED]
> Subject: RE: [AMRadio] PW Supply
>
> It may be the only path to ground for the power su
It may be the only path to ground for the power supply and measuring the
voltage across it may be the way to measure current from the power supply.
A 10 ohm resistor with 1 volt measure across it represents 100ma current.
This is common practice for the way I measure power supply current.
BTW I f
Opps Brett the 5691 is equivalent to the 6SL7 but I could build around that.
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Brett gazdzinski
Sent: Friday, December 01, 2006 8:32 PM
To: 'Discussion of AM Radio in the Amateur Service'
Subject:
Maybe if it is not to complex, you could draw the circuit, reverse
engineer it so to speak. Is this device made of two oscillator circuits
mixed linearly and are they phase shift oscillators or do they have LC
circuits.
Just curious
John
-Original Message-
From: [EMAIL PROTECTED
Class C finals
John Coleman ARS WA5BXO wrote:
> So it would seem that if you replace the 6146 with a 2E26 then in
> order to get the proper operating parameter for the 2E26 one would need to
> reduce the loading. So why not just reduce the loading on the 6146?
The suggestion was to red
Jim, you and I are on the same track here. Many folks make the
assumption the final tubes in a class C circuit are what determines the
power. I look at it from the other end, in that it is the voltage and
loading which determines the power and you have to find a tube that can
handle the sw
I do not have a ranger or have I had a ranger, but I just can't see
how replacing a class C tube will change the power. As far as I know the
ranger is a class C output and not a linear amplifier. To me a class C
circuit is a switch which gains its efficiency from the fact that it doesn't
s
That's a good idea Gary.
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Gary Schafer
Sent: Monday, November 06, 2006 6:56 PM
To: 'Discussion of AM Radio in the Amateur Service'
Subject: RE: [AMRadio] Ranger... good news, bad news
Put a T c
I was going to comment earlier about the statement that this Ranger
would not hold it's on against the rice box with the SB200. As Jim pointed
out there should not be but a DB or so difference if the ranger is working
properly and properly tuned. I am curious as to what power his ranger w
Hi Steve:
In addition to the things that Jim (JKO) said and to answer your
question "is 8.5 volts OK?", (assuming your meter is correct) no 8.5 volts
is not OK. Not only will the emission be low and power out low but the
tubes will suffer from a special illness that occurs from insufficie
That is the way I am running mine Jim. I have two power supplies
(MOD/FINAL) 120 VOLT AC each and I run one from each leg of the 220 and a
common line for the return. (Three Wire). The plate relay/contactor is a
three phase relay/switch but only 2 of the contactors are active of course.
T
Report on the JOTA operations from Galveston Texas.
20 and 40mtrs were really hopping. We were running a TS430s into a
Johnson matchbox connected to a open wire feed line to a center fed 100 ft
doublet stretched between to 30 ft towers. Propagation was all over the
place. On Friday, righ
Yes, by all means give it a whirl. That's how discoveries are made.
Funny, that you should mention the SB200 in that way. BJ, WB5PKD, and I are
using the SB200 to drive the grids of the 250THs. We drive the SB200 with a
modified TS820. The TS 820 put about 10 watts into the SB200 and the SB200
For using the Kenwood TS430 as a VFO to go into the Knight T60, yes
you can use the AM mode with audio gain turned down on the TS430 and put a
dummy load on the TS430. I don't remember what voltage is required at the
T60 input. My guess would be 5 - 10 volts PTP but it has been to long ag
The RCA 1:1 modulation XFMR I believe is good for only 200 ma in its
secondary. Don, K4KYV has described a method of removing or reducing the
core gap to make this XFMR capable of very good low frequency response but
it will then require a modulation reactor and coupling capacitor because the
seco
I see Otis from time to time still I will give him a call and see if we can
dig up some of the old recordings. I have the equipment to do the transfer
to digital. I do it all the time for customers.
John, WA%BXO
__
AMRadio mailing li
In the cannon laser jet SX series printers released as HP Laser Jet II, and
other brands as well, there is a solenoid device which releases a clutch
which then allows the paper pickup rollers to move paper through the
printer. These devices have a felt pad between the armature and the pole
piece w
"Cool tubes" reminds me of an old friend who even though is silent key, I
will not say his name or call. I had a lot of respect for the gentleman
but this was classic. He had wound a very nice ultra large modulation XFMR
and it worked wonderful but was prone to talk back. K5SWK suggested that h
Now that is what I call ham radio ingenuity! Way to go Bob. If for no other
reason just to see if could be done. It reminds me of my experiment to
water cool the 4CX300s. I won't bore you guys with that again.
73
John, WA5BXO
-Original Message-
On Behalf Of W1EOF
Sent: Monday, August 2
K5SWK, Otis, had built several, band switched, 80, 40, 20 mtr
converters using 12 volt tubes. These were the tubes that you found in the
hybrid car radios. These car radios were all tube except for the solid
state output stage. I think they were used about 1960 to 1965 in GMC
vehicles.
Don, K4KYV, sent me a reply direct and said he was not even able to post
reply via the reflector using the text of my message.
Really weird.
John
: Discussion of AM Radio
Subject: Re: [AMRadio] on the air tonight
--- John Coleman ARS WA5BXO <[EMAIL PROTECTED]>
wrote:
> Hey Don, K4KYV
> I may actually be on the air tonight if any one
> wants to fight the QRM.
> John, WA5BXO
>
Hey John,
Any idea what time, an
I sent message2 with out the "HIHI", again and it still bounced again.
John, WA5BXO
This is really strange. I can't seem to get a certain message to go through
regarding something that Don, K4KYV, was talking about. So I posted the
message on my web site. All of the other messages that I send go through
fine. There must be a word in the txt that the reflector doesn't like?
Ple
Hey Don, K4KYV
I may actually be on the air tonight if any one wants to fight the QRM.
John, WA5BXO
Bob
Regarding the need for the 100K pot:
Is The Pot Open?
Or
Is The Switch bad?
I may have some thing that will work.
Is the pot a linear resistance movement or logarithmic. My guess is that it
is linear but the best way to tell is to set the pot at the half way point
between extremes and t
They are also called "CVT" (for Constant Voltage Transformer) I think or is
there a slight difference that I am not aware of??
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Rick Brashear
Sent: Tuesday, May 09, 2006 7:03 PM
To: Discussion of
That's a great idea Jim, about using an RF amp meter for non sinusoidal wave
forms or even DC. I've only had three or four of those but never saw two
that read the same. I was beginning to think that a thermometer in the
dummy load box might be calibrated just as well. HIHI Maybe I just don't
ha
Zenith, GE, and Sylvania TV (older tube versions) sets used the
Ferro resonant transformer or Constant Voltage Transformer (CVT) that had a
special winding with about a 1 to 4mf capacitor across it to saturate the
core. This was there answer to the problems of picture shrinkage when
people
You are correct Gary, it is very confusing to many and I was one
confused guy for many years. It's not easy to get a grip on things of
this nature. Invisible radiation and weird parts that have no movement,
makes it all seem like wizardry and magic. Of course this is what makes
it fascin
Your right Larry, unless it is very large.
I thought it might be an air balun.
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Larry Will
Sent: Tuesday, April 18, 2006 9:04 PM
To: Discussion of AM Radio
Subject: RE: [AMRadio] Zepp Antenna
Th
I suppose the lengths I suggested just would not work in your arena.
The large balun is probably a good idea.
73,
John
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of uvcm inc.
Sent: Tuesday, April 18, 2006 5:23 PM
To: 'Discussion of AM Radio'
Subject: R
This is an edited revision of the email I sent earlier because the first
one did not read properly due to improper spelling and grammar. I was
in a hurry! Sorry
Brad,
The sum of one ant leg and the feed line needs to be about 120 ft or
doubled for 240 ft so as to come out with a high Z for the J
Brad the sum of one ant leg and the feed line needs to be about 120 ft
or 240 ft so as to come out with a high Z for the Johnson match box.
Your lengths or come out with a low Z at the feed point and Johnson
Match Box's don't like that.
John, WA5BXO
-Original Message-
From: [EMAIL PROTE
ubject: RE: [AMRadio] FW: Wanted transformer Gates BC 1 G
I am running balanced line now, I changed the length of the feed line
and
the ant, minor change
Thanks for the info
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of John Coleman ARS
WA5BXO
Sent: Wednesday
1/4 wave length of 500 Ohm bal line will transform it to 250 ohms.
John, WA5BXO
-Original Message-
From: uvcm inc. [mailto:[EMAIL PROTECTED]
Sent: Wednesday, April 12, 2006 3:27 PM
To: 'AMRadio@mailman.qth.net'
Subject: Wanted transformer Gates BC 1 G
How to lower the impendence on a d
I was thinking that I had read an article published by RCA
explaining that the series grid resistor on 807/1625s, 20K as I recall,
was placed in circuit for linearity reasons. It was having something to
do with a dip or a peak in transconductance mid way in the drive. The
solution was sim
I am speaking of high gain audio chassis here Bob. A ground
loop can create all kinds of hum in audio circuitry and you will never
get it right until you get rid of all ground loops especially if a power
XFMR, heater XFMR or power choke is on the same chassis. These are not
transmission l
Don't know about the capacitance Jim. I'll need to measure it.
A few inches haven't made a lot of difference in the high end of the
audio spectrum though, and most of my circuits terminate in 100 K ohms
or less.
I was trying to think of a need for a terminated delay line type thing
where
I really have no idea if it is wired for 110 or 220. I know
that the Plate XFMR is 110VAC and if it were me I would wire a separate
primary circuit for the plate XFMR. Just for the load balance. If the
filaments and low voltage stuff is all run from side A of a 220 circuit
and the plate
I once used a pair of 4cx300 for modulators (weird tube but they
were free). I remember them having the capability of working into low Z
loads in AB1 operation. That is why I wanted to try them. I had a 1:1
modulation XFMR and was running 2000 volts at 400ma with a pair of 813s
in the fin
Original Message-
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of John
> Coleman ARS WA5BXO
> Sent: Sunday, March 26, 2006 9:03 PM
> To: 'Discussion of AM Radio'
> Subject: RE: [AMRadio] Modulator design needed
>
> I haven't actually
I haven't actually built much in the way of audio with 6146 however
OTIS, K5SWK, has done a lot with the tube I am sure it was all standard
tetrode connections. He contends that the screen supply needs to be
well regulated and the control grid leak resistor, if AB1, needs to be
kept low, in the 10
Although the output tubes are 6146s the circuitry of the driver is what
is in question. The older 6SN7 could be replaced with the 5697 9 pin
mini or at lower voltages the 12AU7s could work. The idea of the pahse
splitter is to use a triode with exactly the same resistor for both
plate and cathode
Try this on for size.
http://www.bonavolta.ch/hobby/en/audio/6146.htm
I would recommend a balancing control in the cathode circuit of the
driver stage as the common cathode resistor compensates for
irregularities in the phase splitter it will also cause and improper DC
offset due to a possible
Bill,
There is a switch on the panel of the TS820 and for the life of
me I can't think of what it was used for right now and I'm not at the
shack, but its use was never found inviting so BJ, WB5PKD, and I found a
use for it. You see, the TS-820 uses diode switching to move the XTAL
and SSB
I love this stuff!
John, WA5BXO
-Original Message-Not in its entirety.
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Bob Bruhns
Sent: Thursday, March 16, 2006 10:12 AM
To: Discussion of AM Radio
Subject: Re: [AMRadio] Class AB and B audio XFMRS
Magnetic hysteresis is
Alan, most all tube type linear amps are class B, or AB and can
be single ended or push-pull. In RF service the tank tuning takes care
of the output wave distortion making nice pretty sine waves. Linear
amps are not class C because class C is really more like a switch than
an amplifier. I
This is what I have so for guys, and Larry I quoted you as well hope it
is OK
http://wa5bxo.shacknet.nu/XFMR_losses/audio_transformers1.htm
Now Bacon, You know I can't spell. If any thing is right on that page
it is because of built in spell checking.
I hate getting old
I'm all upside down, my
Very interest Jim:
On magnetic bucking:
I guess just a few turns of some heavy wire would suffice and
the bucking current could be many amps to compensate for the fewer
turns. But the DC CCSource would need to be fee of HUM or any
variations else it would modulate the secondary with a
A pair of 812As should get you about max 360 watts out with 65 watt PD
in intermittent service (CW not AM). I can't see the T55 doing better
with a lower plate dissipation limit.
For those that don't readily have the specs--
812A Class C Plate Modulated (CCS) 45 watt PD
Plate Voltage ..
OK BOB!
You got my attention. Explain more. I hope I'm not a sucker
here. I have seen and extremely low mu amplifier circuit (common
cathode) made by reverse biasing the plate of a triode and forward
biasing the grid where output is taken from the grid and input is on the
plate. So I kno
Construction of a push pull circuit is a real difficult project if
started wrong. It has been my experience to find that the plate tank
and grid tank do need to be as far apart as possible if plug in coils
are to be used and they need to be at right angles to each other. Some
folks choose to use
I have not driven it externally before Craig but have some
experience with the circuitry and the driver XFMR is a weak link in the
circuit the XFMR barely has enough iron and coupling coefficiency in it
to pass the low frequencies that the rig is designed for. As a matter
of fact if the ca
Gary, you are 100% technically correct here on this and I will admit to
being a little arrogant about the statements. I guess this whole thing
is just rubbing me the wrong way. I really am getting to old to put up
with changes any more. And boy, nothing is sacred, they even change the
names of s
Also Jim, you may not need a BFO for CW in the phone band, HIHI.
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of W1EOF
Sent: Monday, January 16, 2006 10:44 PM
To: Discussion of AM Radio
Subject: RE: [AMRadio] Web page appears in opposition t
Just get on 40 meters and consider it a challenge to communicate over
the broadcasting stations. You have as mush right to be there as them.
Start up talking to you neighbor running as much as you can to a low
angle radiator. Be sure your not zero beat. Don't think for a minute
that the heterody
I would be curious as to what the fundamental resonance frequency is and
what the high impedance and low impedance actually is at the feed point
of the antenna without balanced line.
If the feed point at the transmitter end of the line is too low, add or
subtract some feed line. You can also add
I have had one in and out of a 32V3 XMTR several times repairing flood
damage. It's not that hard. The oscillator circuit is not that
complicated. I don't know the same about the 75A4 PTO removal, but if
that is not to bad, then just fined the open resistor or the shorted
capacitor and replace i
ter.
Thanks,
Brian
> Date: Thu, 15 Dec 2005 21:29:10 -0600
> From: "John Coleman ARS WA5BXO" <[EMAIL PROTECTED]>
> Subject: RE: [AMRadio] List Server - PLEASE READ - VERY IMPORTANT
> To: "'Discussion of AM Radio'"
> Message-ID: <[EMAIL PROTECTED]
My outlook folder for "AMRadio" shows over 10500 entries and goes back
to 8/8/2000 I can export it to
1) a dbase type file,
2) a PST for Outlook,
3) or a ASCI delimited file.
And then zip it up and post it on my server.
Which would you like?
John Coleman
WA5BXO
-Original Message-
Hi Bacon
I for one would really like to have a copy of all your writings.
If you get them all together maybe you could email them to me in one
large zip. Let me know how large it is and I will accommodate with the
appropriate setting on my email server. Then, with your permission,
I'll po
It was brought to my attention that my web page was really behind and
that I had left out some links to some very important stuff that Bacon
had done so I have corrected it now I hope.
http://www.qsl.net/wa5bxo
and
http://www.qsl.net/wa5bxo/amtech.html
Let me know if it is all OK now.
John, WA
I don't know if the power supply come from the same XFMR or not but what
does "10 on the knob" mean?
John,
WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of John Lawson
Sent: Wednesday, November 16, 2005 8:02 PM
To: Discussion of AM Radio
Subject: R
I may have missed something here amongst all the messages and I
really am not too familiar with the BC610 but I thought it had variable
loading with an adjustable 3-4 turn link. If so, it should be able to
load into a fairly wide range of loads. On my variable link rig I can
go down to
Hi John,
Ed is correct. Better to be safe.
The effect of an impedance bump is a relative thing. Higher
frequencies are affected more. The position of the bump on the line
will affect its size.
Having a piece of metal near a low Z point on the tuned line
will have l
Depending on how critical your rice box is about having a pure 50 ohm
load on it and the amount of voltage required at the grids of the
amplifier, you may want to use a small tuner between the two but nearest
the amp. If a less critical amount of match is required a balun or .25
wavelength 75 ohm o
Well Brian it seems that Western Electric is the culprit, in
1915s or 1920s. It would be impossible to speak directly with any of the
founders as I'm sure they are gone but I wonder if there are folks that
have a BIO on the individuals that worked on the project.
John, WA5BXO
-Origi
AM ham ops.
Maybe I was given wrong information.
On 18 Sep 2005 at 18:21, John Coleman ARS WA5BXO wrote:
> Yes, AMers are mavericks but I feel that the ones that did not
> go to SSB (100%) back in the 60s and 70s, are the ones that didn't
have
> any trouble communicating wi
Yes, it's true to some extent, for some it may be a hobby as you
described but for a lot of us it is some thing that we look forward to
spending a lot of time with and has become a very major part of our
lives and our families lives, some times to the dismay of others in the
family. I am v
Yes, AMers are mavericks but I feel that the ones that did not
go to SSB (100%) back in the 60s and 70s, are the ones that didn't have
any trouble communicating with whom ever they wanted and for the most
part this took place because they were very knowledgeable folks with a
desire to exper
The "Idea" is for us rednecks, that have a car sitting around
that we don't drive, is not drivable, or we can't afford to buy gas for
it. Truth be known, that a totally sealed up small space such as a
trunk of a car, may not work to well because the "air saturation with
water" would probab
I have a modulation XFMR that was under muddy water for 6
months. I thought it had some how floated away in the "Spring, Tx flood
of 94", But I just didn't understand how it would be possible. That's
another story, where was I, Oh yeh, the XFMR was found and the mud was
off of it. It was
Hey Bob:
I just realized that each Henry of inductance is equivalent to
376.8 ohms at 60 Hz. I don't know why, but at my age now, little
revelations of that nature excite me.
John,
WA5BXO
If it were me planning the broadband solution I would commission
the Telco to do it or be taxed more because I think, as you do Jack,
that the Telco's wires and fiber or more suited for the job. To me, BPL
is like using a 6BK4 (a triode with extremely high gain) for a preamp
but the plate
Sorry about the spelling!
You may want to join in the mail group called AMPS CONTESTING lots of
really smart guys their on linear amps.
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of John Coleman ARS
WA5BXO
Sent: Wednesday, August 03, 2005 9:09 AM
To
Grid driven linear amps are a challenge sometimes even tetrode tubes
need to be neutralized. Neutralization not only prevents spurious
oscillations but it also stops phase modulation products. Swamping the
grid circuit with a dummy load is a good idea because it reduces the 90
degree feedback tha
For those of you that don't know, I am the worlds worst at using
the wrong word and spelling. I don't mind getting corrected. Besides
some of you can't get any jabs in any other time because I am seldom on
the air much. HIHI
Consider WIRLED PEAS
John
WA5BXO
I have been asked a lot about the rig so I will send this out to the
Group.
http://www.qsl.net/wa5bxo/pkd-bxo/rebuild.html
http://wa5bxo.shacknet.nu/HAMPICTURES/Pictures/Ham%20Radio/BIG_Rig.JPG
http://wa5bxo.shacknet.nu/HAMPICTURES/Pictures/Ham%20Radio/Mic.jpg
Movies and audio below provided b
Well to be honest I never saw the inside of one but a friend of
mine had one, at least I think that is what he had. Now I'm not sure.
Was there another model XCVR by Gonset that was similar but had low
level modulation?
I did have a silver faced G-7--- something, mobile XMTR with
s
Jim,
That is an interesting circuit with the plate grounded and
output taken from the screen grid as an anode. I don't quite see the
advantage other than fewer parts. The gain seems to be about 10 db less
if I read it right. Perhaps the screen to grid capacitance is much
lower than an e
Dennis,
I don't have the 1954 Handbook to look at the article but, by
definition, the series modulator is hooked up so that the entire power
supply voltage going to the final is varied in accordance with the bias
or audio on the modulator. It is High Level Plate Modulation, and the
modula
Hi again Larry.
Yes, all this brings back old memories. I quit the TV repair
business back in 1986 (I Think). Anyway started doing PC work and now I
wish I could sometimes just run away and play with my toes in sand. HIHI
CUL, 73
John, WA5BXO
-Original Message-
From: [EMAIL PROT
: [AMRadio] Physical Reality of Sidebands
John,
You are close. That was the old black and white days. Since color its
divided
down from 3.579454 to 15, 726.xx (approx) and vertical is 59,94 not
60.00.
Larry W3LW
On Sun, 16 Jan 2005 22:58:04 -0600, "John Coleman ARS WA5BXO"
<[EMAIL
Don, I have often pondered the same thing here is another example.
The Horizontal sweep rate of a TV is 15750 hz. Every 1/15000 of
a sec there is a sync pedestal, and on the back porch of it is a burst
of a few cycles (as I remember it was 8 to 10 cycles in length) of the
color sub carri
It's probably down for maintenance.
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Geoff
Sent: Thursday, January 06, 2005 7:12 PM
To: Discussion of AM Radio
Subject: [AMRadio] QSL.Net
Is QSL.Net gone?
All I get is "The Connection was refus
Perhaps I missed it but why would you want to change the 845 driver
circuit, are you missing the tubes?
John, WA5BXO
Very good point Don
John, WA5BXO
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Donald Chester
Sent: Sunday, January 02, 2005 6:04 PM
To: amradio@mailman.qth.net
Subject: [AMRadio] Metering circuits
One word of caution. If you use the above circuit
What your speaking of Don is shown in the following article.
http://www.qsl.net/wa5bxo/pptriodes/pptriodes.htm
This article was started some time ago, for what reason I don't
remember. I never had the chance to spend a lot of time with it so it
probably has a lot of mistakes. I
I gather from the text about the HV meter and current meter that the
current meter is above ground by 4000 Volts. I know that there are a
lot of special mounting devices and hardware for this purpose but I
still feel that it is a bad idea. I have always made sure that HV
current metering was done
Here is some more superfluous (also unnecessary) info:
The reciprocal of "reactance" is "susceptance". In a series circuit the
"reactances" are null, at resonance, leaving only low resistance (OHMS).
In a parallel circuit the "susceptances" are null, at resonance, leaving
low conductance (MHOS).
, November 23, 2004 6:25 AM
To: Discussion of AM Radio
Subject: RE: [AMRadio] AM Usage with Linear AMPS
I thought that the WRL DuaoBander mobile was only SSB.
On 22 Nov 2004 at 22:11, John Coleman, ARS WA5BXO wrote:
> My experience (which is very little when it come to these sweep tube
> rigs) i
Hi Brian:
Consider what the efficiency is with no drive. The tube is drawing
current and has voltage therefore it has input power but no output.
Efficiency is 0%.
As input drive is applied the efficiency increases but so does the plate
current. The trick is to reach the 25% power point (or 50 Vo
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