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


Mike Sawyer w3slk at uplink.net
Fri Oct 28 16:40:07 EDT 2005


Just proves the theory: Ignorance is bliss....
Mike(y)
W3SLK
----- Original Message ----- 
From: "Jim Candela" <jcandela at prodigy.net>
To: <Amradio at Mailman.Qth.Net>
Sent: Friday, October 28, 2005 9:10 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)
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> >
> > --
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > 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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