MW pre selector
 

Now I know this is a bit OT, but can anyone recommend me any sites on how to
build a pre selector for the MW band. Several times tried google searches,
but only came up with commerical ones, and ideally I would like to build one
myself.

Any leads greatly appreciated,

Richard, Warsaw

Richard -
The manual for an RME DB22-A preselector, available for download at the BAMA
archive
http://bama.edebris.com/manuals/rme/db22a/ should give you some ideas.

--Chuck
"Richard" wrote in message
...
Now I know this is a bit OT, but can anyone recommend me any sites on how
to
build a pre selector for the MW band. Several times tried google searches,
but only came up with commerical ones, and ideally I would like to build
one
myself.

Any leads greatly appreciated,

Richard, Warsaw

Simplest one you can make is by taking the main tuning capacitor and ferrite
rod antenna out of an old AM radio, wiring them in parallel, then putting that
circuit in series with your antenna. That will allow you to peak the frequency
you're tuned to, reducing all others. If you wire that circuit (an LC circuit)
from your antenna to ground, it will notch the frequency it's tuned to ...
kinda handy if you've got a local pest that splatters across the bands.

jw
K9RZZ

JW,

Sort of like the "Quantum Stick Plus+" by RadioPlus+
http://www.dxtools.com/QStick.htm

Built one of these back in the early 1960s from a PopElectronics
Article. Worked Great as both an AM/MW Antenna Tuner and an
Antenna Coupler for 'portable' AM/MW Radios.

NOTE: Back in the early 1960s I managed to receive "WBZ" in
Boston using a Hitachi TH-812 (TRF AM/MW Portable Radio) with
an outboard 'inductively coupled' Tunable Ferrite Rod Antenna
Feed by a 65 Foot Random Wire Antenna.
GoTo= http://www.transistor.org/collection.../hitachi9.html
NOTE: This took me Two Winter Seasons to Log this DX Catch.

Thats' All Folks ~ RHF
..
..
= = = (J999w) wrote in message
= = = ...
Simplest one you can make is by taking the main tuning capacitor and ferrite
rod antenna out of an old AM radio, wiring them in parallel, then putting that
circuit in series with your antenna. That will allow you to peak the frequency
you're tuned to, reducing all others. If you wire that circuit (an LC circuit)
from your antenna to ground, it will notch the frequency it's tuned to ...
kinda handy if you've got a local pest that splatters across the bands.

jw
K9RZZ

Thanks for the replies,

BUT what I still needs is a pre selector, a la palstar's MW550p unit, rather
than an active aerial or pre amp or ATU. I have an ATU and I can make a pre
amp, but I would like to find a circuit diagram for a really selective (6khz
bandwidth) pre selector like the palstar unit

Rgds
Richard

"Richard" wrote in message
...
Now I know this is a bit OT, but can anyone recommend me any sites on how
to
build a pre selector for the MW band. Several times tried google searches,
but only came up with commerical ones, and ideally I would like to build
one
myself.

Any leads greatly appreciated,

Richard, Warsaw

"Richard" wrote in message
...
| Now I know this is a bit OT, but can anyone recommend me any sites on how
to
| build a pre selector for the MW band. Several times tried google searches,
| but only came up with commerical ones, and ideally I would like to build
one
| myself.
|
| Any leads greatly appreciated,
|
| Richard, Warsaw

That's a good idea, Richard.

I, too, would find this kind of project interesting.
Another one which would be fun and useful
is a phasing unit that allows for the phasing of
2 dipoles.

73,

Steve Lawrence
KAØPMD
Burnsville, Minnesota

(NOTE: My email address has only one "dot."
You'll have to edit out the one between the "7"
and the "3" in my email address if you wish to
reply via email)


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In article ,
J999w wrote:
Simplest one you can make is by taking the main tuning capacitor and ferrite
rod antenna out of an old AM radio, wiring them in parallel, then putting that
circuit in series with your antenna. That will allow you to peak the frequency
you're tuned to, reducing all others. If you wire that circuit (an LC circuit)
from your antenna to ground, it will notch the frequency it's tuned to ...
kinda handy if you've got a local pest that splatters across the bands.

You've got that reversed. A parallel tuned circuit has its highest
impedance at resonance, so if you put it in series with the antenna,
it will act as a notch filter. In parallel with the antenna circuit,
it will as a selector, causing off resonance signals to be reduced.
Better performance may be obtained by tapping down on the winding, or
by using a small link winding, as the receiver's antenna input may be
loading down the tuned circuit.

One confusion is that if you use an unshielded loopstick, it's acting
as an antenna, too.

Mark Zenier Washington State resident

"Richard" wrote:
| Stephen, see the MW DX group at http://www.mwcircle.org/ and check out
the
| MWC Reprint Catelogue, some great stuff
|
| Such as LIL-1, Loop and Wire Phaser
| A new circuit for combining signals from loop and end-fed antennas.
|
| MWDX-6 Phasing Unit
| Detailed construction and operating notes for this advanced
| antenna phasing unit. Experience essential.
| 32pp £3.80 09/94 M Connelly
|
|
| etc,
|
| Good Hunting and let me know how things go!
|
| Rgds
| Richard, Warsaw

Dziekuje, Richard - I've been looking and drooling
simultaneously.

Now, I've got a problem: How can I hide such a
purchase from my wife?

(grinning)

Dzien dobry,

Steve Lawrence
Burnsville, Minnesota


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"Stephen M.H. Lawrence" wrote ...

Dziekuje, Richard - I've been looking and drooling
simultaneously.

Now, I've got a problem: How can I hide such a
purchase from my wife?


Hide this, Bro. Lawrence. http://palstar.com/MW550p.htm .
Laid hands on one at Dayton last weekend - sccccchhhhweeeeet .. and
they've cut the price on it since last year. Seems like it was always
$349 till this time.

NOTE: Back in the early 1960s I managed to receive "WBZ" in
Boston using a Hitachi TH-812 (TRF AM/MW Portable Radio) with
an outboard 'inductively coupled' Tunable Ferrite Rod Antenna
Feed by a 65 Foot Random Wire Antenna.
GoTo= http://www.transistor.org/collection.../hitachi9.html
NOTE: This took me Two Winter Seasons to Log this DX Catch.

Thats' All Folks ~ RHF
.
.
= = = (J999w) wrote in message
= = = ...
Simplest one you can make is by taking the main tuning capacitor and
ferrite
rod antenna out of an old AM radio, wiring them in parallel, then putting
that
circuit in series with your antenna. That will allow you to peak the
frequency
you're tuned to, reducing all others. If you wire that circuit (an LC
circuit)
from your antenna to ground, it will notch the frequency it's tuned to ...
kinda handy if you've got a local pest that splatters across the bands.

jw
K9RZZ







NOTE: Back in the early 1960s I managed to receive "WBZ" in
Boston using a Hitachi TH-812 (TRF AM/MW Portable Radio) with
an outboard 'inductively coupled' Tunable Ferrite Rod Antenna
Feed by a 65 Foot Random Wire Antenna.
GoTo= http://www.transistor.org/collection.../hitachi9.html
NOTE: This took me Two Winter Seasons to Log this DX Catch.

Now that seemed to be a sweet catch, especially on that piece. Did you qsl by
chance?

~^Monitoring The Spectrum^~
Hammarlund HQ129X /Heathkit Q Multiplier
Hammarlund HQ140X
Multiple GE P-780's(GREAT BCB Radios)
RCA Victor *Strato- World*
RCA Victor RJC77W-K(Walnut Grain)
1942 Zenith Wave Magnet 6G 601M
Cathedral/ Ross#2311/Rhapsody-MultiBand
DX100/394/*SUPER*398/399/402
OMGS Transistor Eight/Realistic 12-1451
Henry Kloss Model One/Bell+HowellSW
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Alpha Delta DX Sloper 57ft.
500ft. 12AWG. (non-terminated)
120ft. 12 AWG Long-Wire
2 Radio Shack Loop Antennas
Radio Shack Amplified Antenna
30X30 DiamondLoop(six section 830pf Cap)
* Diamond Loop mounted to Lazy Susan TurnTable*
*21/2X2ft.FiveSpoked~Penta-Loop~PancakeLoop*
~OptimusCTR-111Cassettte Recorder~
~Radio Shack 2Speed VOX#43-476~
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