Hi

wonder if it is some particular difference between the terms "magnetic
antenna" and "frame antenna" ? Somebody seems to have the opinion that
the second is just a popular new word for the first, and it is no real
difference. I would believe that a frame antenna could be a single
winding antenna with high impedance connection on to the grid or gate
of an amplifier or mixer, while the magnetic version has inductive
coupling.

I've tested some of the latter type on 136kHz and MF, and it seems
that it is no need for an amplifier to improve the signal, it only
lowers the signal to noise, and possibly put too strong signal into
the receiver. On 136kHz the tuning is extremely sharp, and remote
control is a must, see http://home.online.no/~la8ak/L2.htm , if a
large frequency range should be covered, use two varicaps should be
connected in electrical-anti-paralell (not DC), it is easily possible
to cover the 500-1600kHz band with remote tuning.

73
Jan-Martin
LA8AK
http://home.online.no/~la8ak/c.htm
----
Jan-Martin, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/

I'm sure the terms must mean slightly (or more) different things to
different people. To me, a "frame antenna" is a loop which is
specifically rectangular (or square) like most common picture frames,
but could possibly have a perimeter that's a significant fraction of a
wavelength. And to me, a "magnetic antenna" (as opposed to a
magnetic-mount antenna) is a loop which might be a frame or a circle,
but has a perimeter which is definitely quite short compared with a
wavelength, so that it has low response to electric fields. Both are
"loop antennas," and the magnetic antenna is often called a magnetic
loop. To be clear, you might say, "square magnetic loop" or "circular
magnetic loop" or whatever, and get even more specific by calling out
the perimeter in wavelengths.

Cheers,
Tom

"Jan-Martin Noeding, LA8AK" wrote in message . ..
Hi

wonder if it is some particular difference between the terms "magnetic
antenna" and "frame antenna" ? Somebody seems to have the opinion that
the second is just a popular new word for the first, and it is no real
difference. I would believe that a frame antenna could be a single
winding antenna with high impedance connection on to the grid or gate
of an amplifier or mixer, while the magnetic version has inductive
coupling.

I've tested some of the latter type on 136kHz and MF, and it seems
that it is no need for an amplifier to improve the signal, it only
lowers the signal to noise, and possibly put too strong signal into
the receiver. On 136kHz the tuning is extremely sharp, and remote
control is a must, see http://home.online.no/~la8ak/L2.htm , if a
large frequency range should be covered, use two varicaps should be
connected in electrical-anti-paralell (not DC), it is easily possible
to cover the 500-1600kHz band with remote tuning.

73
Jan-Martin
LA8AK
http://home.online.no/~la8ak/c.htm
----
Jan-Martin, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/

I'm sure the terms must mean slightly (or more) different things to
different people. To me, a "frame antenna" is a loop which is
specifically rectangular (or square) like most common picture frames,
but could possibly have a perimeter that's a significant fraction of a
wavelength. And to me, a "magnetic antenna" (as opposed to a
magnetic-mount antenna) is a loop which might be a frame or a circle,
but has a perimeter which is definitely quite short compared with a
wavelength, so that it has low response to electric fields. Both are
"loop antennas," and the magnetic antenna is often called a magnetic
loop. To be clear, you might say, "square magnetic loop" or "circular
magnetic loop" or whatever, and get even more specific by calling out
the perimeter in wavelengths.

Cheers,
Tom

"Jan-Martin Noeding, LA8AK" wrote in message . ..
Hi

wonder if it is some particular difference between the terms "magnetic
antenna" and "frame antenna" ? Somebody seems to have the opinion that
the second is just a popular new word for the first, and it is no real
difference. I would believe that a frame antenna could be a single
winding antenna with high impedance connection on to the grid or gate
of an amplifier or mixer, while the magnetic version has inductive
coupling.

I've tested some of the latter type on 136kHz and MF, and it seems
that it is no need for an amplifier to improve the signal, it only
lowers the signal to noise, and possibly put too strong signal into
the receiver. On 136kHz the tuning is extremely sharp, and remote
control is a must, see http://home.online.no/~la8ak/L2.htm , if a
large frequency range should be covered, use two varicaps should be
connected in electrical-anti-paralell (not DC), it is easily possible
to cover the 500-1600kHz band with remote tuning.

73
Jan-Martin
LA8AK
http://home.online.no/~la8ak/c.htm
----
Jan-Martin, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/