[AMRadio] Fwd: Re: Kitset HF Linear amp.


crawfish crawfish at surfmore.net
Fri Oct 28 19:21:11 EDT 2005


This guy Andy sounds like some of the folks around here on 2m FM repeaters.
I'll bet he "shoots skip" with all the good buddy lids on 11m. As Hank Hill
would say"That boy ain't right!!"
                                   Joe W4AAB
----- Original Message -----
From: "Jim Candela" <jcandela at prodigy.net>
To: <Amradio at Mailman.Qth.Net>
Sent: Friday, October 28, 2005 8:10 AM
Subject: [AMRadio] Fwd: Re: Kitset HF Linear amp.


>
> Group,
>
> Well here is what the buyers of this linear amplifier
> are getting. See Andy's statement below in his own
> words. I think that tells it all.
>
> Jim
> --- supersparks <pirateradiofm at xtra.co.nz> wrote:
>
> > From: "supersparks" <pirateradiofm at xtra.co.nz>
> > To: "Jim candela" <jcandela at prodigy.net>
> > Subject: Re: Kitset HF Linear amp.
> > Date: Sat, 29 Oct 2005 00:30:53 +1300
> >
> > jim, all your goggleygook means zero to me, im only
> > interested in what my
> > bird watt meter states, and it states as i claim, im
> > not about to tell the
> > bird watt meter company that there meters are in
> > error.
> > Not all theory is correct and can be interperated
> > several ways, but when the
> > standard test is the use of a bird watt meter then i
> > choose to run with its
> > findings, thx andy
> > ----- Original Message -----
> > From: "Jim candela" <jcandela at prodigy.net>
> > To: "supersparks" <pirateradiofm at xtra.co.nz>
> > Cc: "Amradio at Mailman.Qth.Net"
> > <amradio at mailman.qth.net>
> > Sent: Friday, October 28, 2005 3:07 PM
> > Subject: RE: Kitset HF Linear amp.
> >
> >
> > >
> > > Andy Said at alt.binaries.schematic :
> > >
> > > hi again all.
> > > I have a kitset HF linear amp available, send an
> > email to
> > > pushpullamps at yahoo.co.nz for information and
> > payment options.
> > > Disclaimer: These amps cover 3-30mhz, it is
> > illegal in most countries to
> > use
> > > such equipment on the citizen bands.Proper use of
> > this equipment lays
> > > entirely with the user.
> > >
> > > Heres what you get:
> > >
> > > Etched PCB ready to load.
> > > ALL components.
> > > Heatsink.
> > > Full Schematic.
> > > Parts Layout.
> > > FEATURES:
> > > · Broadbanded (3-30 MHz) push-pull design. No
> > tuning required after a
> > simple
> > > one-time setup procedure.
> > > · Power levels: 100Watts AM, 180Watts PEP.
> > > · Now includes trimmer adjustable input and output
> > tuned circuits for
> > > perfect SWR matching. Just set it and forget it.
> > > · All mode operation: AM, FM, CW, SSB.
> > > · Internal SWR protection with rugged transistors.
> > > · Bias switching lets you choose the most
> > efficient method for Class C
> > > (AM/FM/CW) or Class AB (SSB) operation.
> > > · Carrier operated T/R relay with separate
> > drop-out timing delays to
> > > automatically match AM/FM or SSB operation.
> > > · Switchable ON/OFF operation with LED indicator.
> > > · Jumper adjustable input network matches 4-10W RF
> > drive levels for most
> > > popular HF transceivers.
> > > · Transient spike protection in mobile use.
> > > · Double-sided PCB design for excellent RF
> > stability and voltage
> > regulation.
> > >
> > > Kindest regards andy jackson (RF Radio Engineer)
> > >
> > >
> > >
> > > Reply by Jim Candela, WD5JKO:
> > >
> > > Andy,
> > >
> > >     You need to provide test data including
> > schematic, and waveforms while
> > > running at 100 watts carrier output, and then show
> > the modulated envelope
> > at
> > > 100% peak + (upward) AM modulation (w/o severe
> > distortion). Do this to the
> > > alt.binaries.schematic group, not just me. If you
> > do, I'm sure you will
> > make
> > > more sales of your kit, and if the thing really
> > does that, I'll endorse
> > your
> > > kit for any use other than CB. To a CB trucker, a
> > real 100 watt (carrier)
> > > amp that modulates to at least 90% peak + is a
> > treasure.
> > >
> > >     Now please understand that with a sine wave
> > audio drive, at 100 %
> > > modulation the amplifier must peak at 400 watts
> > PEP, and a watt meter
> > > (average responding) will read 150 watts. For AM
> > at 100% modulation, each
> > > side band is 6 db below the carrier power. As you
> > know 6 db in power terms
> > > is 1/4th (or 4), so for a 100 watts carrier power,
> > you get 25 watts (avg)
> > in
> > > each side band. So the carrier stays at 100, and
> > you get 100+25+25=150
> > watts
> > > average.
> > >
> > >     Now the crux where your amp will fall short,
> > is that 400 watts PEP is
> > > unobtainable. I'm sure you will agree with that
> > statement. The problem
> > with
> > > AM linear amps is that they need the headroom to
> > peak to 4X the carrier
> > > power when modulated. This means that the
> > amplifier output voltage doubles
> > > from carrier level, and since E^2/R=W, if the
> > voltage doubles, the power
> > > quadruples.
> > >
> > > Following are the formulas for finding AM
> > Modulation depth:
> > >
> > > PEAK + method: m = 100 * ((Emax - Eavg) / Eavg )
> > >
> > > PEAK - method: m = 100 *((Eavg-Emin)/Eavg)
> > >
> > > The above information is not something I made up.
> > >
> > > Most amateur transceivers are rated at 100 watts
> > PEP output for SSB. Most
> > of
> > > the ones that include AM state that the maximum
> > output is 25 watts
> > carrier.
> > > This is limited to 25 watts AM because the ALC is
> > designed to kick in at
> > 100
> > > watts PEP. Some other transceivers change the ALC
> > from peak responding to
> > > average responding for AM, and this allows them to
> > rate AM at 40 watts
> > > carrier. At 40 watts 100% modulated, you get 160
> > watts PEP. Your kit-amp
> > > should do that fine, but not 100 watts. Don't you
> > see, or understand what
> > > I'm talking about? These transceivers all have a
> > power amplifier board
> > > similar to yours.
> > >
> > > Most CB transceivers will easily modulate to at
> > least 85%. Using the above
> > > formulas, does the output of your amplifier do the
> > same at the power level
> > > you claim?
> > >
> > > The Motorola application notes I referred to at
> > the hyperlink in my last
> > > post did show an amplifier running off 13.8 volts,
> > and ran 100 watts AM.
> > In
> > > fact this amplifier is very similar to yours. The
> > problem with this
> > though,
> > > is that when tone modulating, the upward
> > modulation was limited to 20-25%.
> > I
> > > don't call this AM since IT IS OVERLOADED,
> > COMPRESSED, AND DISTORTED.
> > >
> > >
> >
> http://pages.prodigy.net/jcandela/AM_Linear/AM%20Linear%20Operation.pdf
> > >
> > >
> > > So how can you continue to stand by your
> > specifications? They don't
> > compute.
> > > I think you mean 100 watts PEP AM, and 180 watts
> > PEP SSB. If so, then the
> > > only problem here is that AM is normally rated in
> > carrier power assuming
> > the
> > > designer did the rating while allowing for 4X that
> > power at modulation
> > > peaks. So when you say 100 watts AM to you refer
> > to PEP power, or
> > > unmodulated carrier power with 100% peak +
> > modulation capability?
> > >
> > > Do you also stand by running the amplifier bias
> > set to class C on AM? Yes
> > > you can get away with this because it's really
> > class B, however the
> > > crossover distortion from NO bias is there, and
> > does cause visible
> > (scope),
> > > and audible (receiver) distortion. Running SSB in
> > class B with crossover
> > > distortion sounds far worse.
> > >
> > > Yes I may be an arse at times, that is true. That
> > however isn't the issue.
> > > The issue is what you market, and what you say it
> > does is not possible. I
> > > know that, and I think you do too. If your half
> > the engineer that you say
> > > you are, then you understand what I am talking
> > about. Then again maybe you
> > > knew all of this from the beginning, and your
> > marketing strategy is to
> > make
> > > false claims, and sell kits to the uninformed.
> > >
> > > Regards,
> > > Jim Candela
> > > WD5JKO
> > >
> > > -----Original Message-----
> > > From: supersparks
> > [mailto:pirateradiofm at xtra.co.nz]
> > > Sent: Thursday, October 27, 2005 4:51 AM
> > > To: Jim Candela
> > > Subject: Re: Kitset HF Linear amp.
> > >
> > >
> > > it works as i say it does, i dont need to validate
> > my statements to you or
> > > anyone else, stop being a know it all, no one
> > likes smart asses, i
> > garrentee
> > > my product, that is all that matters here.
> > >
> > >
> > > ----- Original Message -----
> > > From: "Jim Candela" <jcandela at prodigy.net>
> > > To: "supersparks" <pirateradiofm at xtra.co.nz>
> > > Sent: Tuesday, October 25, 2005 3:34 AM
> > > Subject: Re: Kitset HF Linear amp.
> > >
> > >
> > > >
> > > > OK, I am listening. Please explain why I am
> > incorrect.
> > > > I think maybe we can both learn something.
> > > >
> > > > Jim
> > > > --- supersparks <pirateradiofm at xtra.co.nz>
> > wrote:
> > > >
> > > > > that is incorrect
> > > > > ----- Original Message -----
> > > > > From: "JC" <jcandela at prodigy.net>
> > > > > Newsgroups: alt.binaries.schematics.electronic
> > > > > Sent: Monday, October 24, 2005 2:41 PM
> > > > > Subject: Re: Kitset HF Linear amp.
> > > > >
> > > > >
> > > > > >
> > > > > > Beware, this is another splatter making CB
> > linear
> > > > > amplifier. Here is why:
> > > > > >
> > > > > > >Power levels: 100Watts AM, 180Watts PEP
> > > > > >
> > > > > > ** If the power is really 180 watts PEP,
> > then the
> > > > > AM carrier power maximum
> > > > > > is 25% of that or 45 watts ---NOT 100 watts.
> > In
> > > > > fact to be clean, and
> > > > > linear
> > > > > > I wouldn't run more than 25 watts output on
> > AM
> > > > > (100 watts PEP).
> > > > > >
> > > > > > >Bias switching lets you choose the most
> > efficient
> > > > > method for Class C
> > > > > > >(AM/FM/CW) or Class AB (SSB) operation.
> > > > > >
> > > > > > ** For linear amplification of AM or SSB you
> > need
> > > > > class A, or AB ---NOT
> > > > > > class C
> > > > > >
> > > > > > Most CB radios when exciting an amplifier
> > such as
> > > > > this will overdrive the
> > > > > > amplifier, and result in significant
> > distortion,
> > > > > and splatter. A 3-6 db
> > > > > pad
> > > > > > between the exciter and amplifier is usually
> > > > > needed to prevent this. Most
> > > > > CB
> > > > > > rigs have 15 - 20 watts PEP output (about 4
> > watts
> > > > > carrier AM) -- too much
> > > > > > for this amp. Very few Ham operators would
> > buy
> > > > > this kit. We all know the
> > > > > end
> > > > > > users are CB'ers who choose to operate
> > illegally.
> > > > > >
> > > > > > > Now includes trimmer adjustable input and
> > output
> > > > > tuned circuits for
> > > > > > perfect SWR matching. Just set it and forget
> > it.
> > > > > >
> > > > > > ** Yea custom designed to work best between
> > 27 and
> > > > > 27.5 Mhz
> > > > > >
> > > > > > I have converted several of these boot-leg
> > CB
> > > > > linears to use on 10 meters
> > > > > > AM, and they all required significant effort
> > to
> > > > > get the gain, and
> > > > > linearity
> > > > > > within accepted amateur radio standards. Of
> > course
> > > > > for CB, all that is out
> > > > > > the window. Just connect and drop the
> > hammer! "hey
> > > > > good buddy, your S9+40
> > > > > on
> > > > > > channel 19, and S9 on channels 1, and 40 all
> > at
> > > > > the same time!"
> > > > > >
> > > > > > Jim
> > > > > >
> > > > > >
> > > > > >
> > > > > > "andy" <pirateradiofm at xtra.co.nz> wrote in
> > message
> > > > > >
> > news:EAn6f.1915$S24.133359 at news.xtra.co.nz...
> > > > > > > hi again all.
> > > > > > > I have a kitset HF linear amp available,
> > send an
> > > > > email to
> > > > > > > pushpullamps at yahoo.co.nz for information
> > and
> > > > > payment options.
> > > > > > > Disclaimer: These amps cover 3-30mhz, it
> > is
> > > > > illegal in most countries to
> > > > > > > use
> > > > > > > such equipment on the citizen bands.Proper
> > use
> > > > > of this equipment lays
> > > > > > > entirely with the user.
> > > > > > >
> > > > > > > Heres what you get:
> > > > > > >
> > > > > > > Etched PCB ready to load.
> > > > > > > ALL components.
> > > > > > > Heatsink.
> > > > > > > Full Schematic.
> > > > > > > Parts Layout.
> > > > > > > FEATURES:
> > > > > > > · Broadbanded (3-30 MHz) push-pull design.
> > No
> > > > > tuning required after a
> > > > > > > simple
> > > > > > > one-time setup procedure.
> > > > > > > · Power levels: 100Watts AM, 180Watts PEP.
> > > > > > > · Now includes trimmer adjustable input
> > and
> > > > > output tuned circuits for
> > > > > > > perfect SWR matching. Just set it and
> > forget it.
> > > > > > > · All mode operation: AM, FM, CW, SSB.
> > > > > > > · Internal SWR protection with rugged
> > > > > transistors.
> > > > > > > · Bias switching lets you choose the most
> > > > > efficient method for Class C
> > > > > > > (AM/FM/CW) or Class AB (SSB) operation.
> > > > > > > · Carrier operated T/R relay with separate
> > > > > drop-out timing delays to
> > > > > > > automatically match AM/FM or SSB
> > operation.
> > > > > > > · Switchable ON/OFF operation with LED
> > > > > indicator.
> > > > > > > · Jumper adjustable input network matches
> > 4-10W
> > > > > RF drive levels for most
> > > > > > > popular HF transceivers.
> > > > > > > · Transient spike protection in mobile
> > use.
> > > > > > > · Double-sided PCB design for excellent RF
> > > > > stability and voltage
> > > > > > > regulation.
> > > > > > >
> > > > > > > Kindest regards andy jackson (RF Radio
> > Engineer)
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > >
> > > --
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> > > Version: 7.1.361 / Virus Database: 267.12.5/149 -
> > Release Date: 10/25/2005
> > >
> > > --
> > > No virus found in this outgoing message.
> > > Checked by AVG Free Edition.
> > > Version: 7.1.361 / Virus Database: 267.12.5/149 -
> > Release Date: 10/25/2005
> > >
> >
> >
>
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