I realize the type acceptance applied to commercially made equipment.
However, I find it odd that a licensed amateur can build an amp that
violates the regulations the commercial builders are required to
follow. (I.E. Drive power) I'm not doubting it; just find it a little
odd. :-)

Also, if I remember correctly, a licensed amateur can build ONE RF Amp
in one calendar year. Anyone building more than one amp must apply for
an FCC grant or type acceptance. (Again, please correct me if I'm
wrong) I remember reading this in the ARRL handbook in the late 90's,
that was over five years ago so this law may have changed.

Are there any ARRL publications, especially the handbook, which contain
plans for a linear amp which will run on 5-25 watts drive power?


Chuck Harris wrote:
First, IANAL, but this is the internet, so here goes:

Type acceptance does apply to linear amplifiers commercially "made
for amateur"
use. There are requirements that the amplifier not be usable above
the 15 meter
band, and not be usable with drive levels below 50 watts. There are
also rules
about how far below carrier the spurious emissions must be. In order
for a
commercial entity to sell a linear amplifier for amateur use, in the
US, it must
be type accepted.

The Palomar Elite is a commercially built linear amplifier that was
not type
accepted. As a result, the sale of the linear amplifier in the US
was
illegal. Any use of the linear amplifier (amateur or otherwise) is
also illegal.

When Heath sold the SB220 and other linears, after the law came into
effect,
they made the amplifiers only work to 15 meters. You could buy a kit
that
would allow operation on 10 meters, but only after showing them a
valid
amateur radio license. Notice that these amplifiers were compliant
with the
FCC rules even though they were kits!

Now, for the other side of the coin: A licensed amateur radio
operator may
build and use *anything* he wants, as long as it meets the
requirements for
the service. He may also modify the radios from any service to be
usable in
the amateur radio service. So, if you have an 11 meter CB, and you
modify
it to operate on 10 meters, that is fine. If you want to build an
amplifier
that takes the 10W or so SSB from that transceiver, and boosts it to
a full
gallon, that is fine too.

The type acceptance laws only apply to the commercial manufacturer.
The
big question before the house is: can an illegally manufactured and
sold product
ever become legal to possess and use? The legal answer is probably
not,
in spite of the fact that it would be perfectly legal for an amateur
to build
such a product for his own use.

-Chuck Harris

Dennis wrote:
I realize the type acceptance applied to commercially made equipment.
However, I find it odd that a licensed amateur can build an amp that
violates the regulations the commercial builders are required to
follow. (I.E. Drive power) I'm not doubting it; just find it a little
odd. :-)

Licensed amateurs can do all kinds of things that commercial manufacturers
cannot do! You don't have to meet a lot of the electrical safety requirements,
even.

For a long time, commercial broadcasters were also allowed to use non-type-accepted
equipment as long as it had markings on the case saying who constructed it and
when, and certifying that it met the requirements of the type. BUT, they could
not sell such a homebrew transmitter to another station for use.

Also, if I remember correctly, a licensed amateur can build ONE RF Amp
in one calendar year. Anyone building more than one amp must apply for
an FCC grant or type acceptance. (Again, please correct me if I'm
wrong) I remember reading this in the ARRL handbook in the late 90's,
that was over five years ago so this law may have changed.

I don't remember that at all but it may well be true. I recently built a receiver
which had ten RF amp modules in the IF strip. Does that violate the requirements?

Are there any ARRL publications, especially the handbook, which contain
plans for a linear amp which will run on 5-25 watts drive power?

Probably some of the older ones do. I know that QST once did a project on
an amp for the ARC-5 sets.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Dennis" ) writes:
I realize the type acceptance applied to commercially made equipment.
However, I find it odd that a licensed amateur can build an amp that
violates the regulations the commercial builders are required to
follow. (I.E. Drive power) I'm not doubting it; just find it a little
odd. :-)

But this is because the rules are about commercially manufactured
amplifiers, not general rules that apply to the amateur service.

Again, we are not talking about laws intended for hams. This amplifier
law is about amplifiers that are illegally used for cb or bootleggers.
The only reason it impacts on amateur radio is because there is no real
way of making an amplifier that only works on ten meters, and not at
all on adjacent frequencies.

How do restrict amplifiers that use to be labelled "illegal for Class
D Citizen Band use" even though they were on the same page as the CB sets?
Well, you can start by requiring drive power that is higher than CB
sets put out. Yes, hams can require amplifiers that use little drive, but
generally it was easy to see from the drive specs what amplifiers were
intended for illegal CB use.

Put in rules that do not allow amplifiers that cover the frequency range.
Hence the elimination of 10meter position on amplifiers intended for ham
radio.

And so on, for whatever the rules state exactly.

The rules will be a problem to some hams, but relatively few. Only a handful
will need low drive requirements. Since it's amateur radio, the individual
has a greater chance of knowing how to fix the problem of no 10meter band on
the amps. And of course, since it's amateur radio, they can always build what
they need. The rules haven't changed amateur radio, they've changed the state
of commercial amplifiers.

Also, if I remember correctly, a licensed amateur can build ONE RF Amp
in one calendar year. Anyone building more than one amp must apply for
an FCC grant or type acceptance. (Again, please correct me if I'm
wrong) I remember reading this in the ARRL handbook in the late 90's,
that was over five years ago so this law may have changed.

That's because you have to define "manufactured". If an individual can
make an amplifier and sell it, then it bypasses the issue completely,
because it still makes amplifiers available for illegal use. One amplifier
a year (and it may specifically say one of the same design), should not
be a hardship for a ham, because realistically they won't need anymore.


Are there any ARRL publications, especially the handbook, which contain
plans for a linear amp which will run on 5-25 watts drive power?



Of course they are, though who knows if they are shown as stand alone units.
After all, one has to build a linear to get low level stages up to a higher
power. And given current design, they are likely to be broadband amplifiers,
with external filtering.

If you don't see stand alone amplifiers, that's because there is little
need. Most rigs already put out more power than the 50watts or whatever.

Michael VE2BVW

Dennis wrote:
snip
Are there any ARRL publications, especially the handbook, which contain
plans for a linear amp which will run on 5-25 watts drive power?

Yes, the ARRL Handbook for 1965 had a single-tube 811A linear.
15W peak input or so should give 150W peak output.

73,
Ed Knobloch