Grundig Satellit 800 Millennium AM/MW Antenna MOD ? ? ?
RHF
800 Millennium AM/MW Ferrite Rod Antenna?
.
Description of the GS800M AM/MW Antenna Circuit:
The "Ferrite Rod Antenna" feeds directly into a "AM/MW Antenna
Pre-Amplifier" with a side input to this amplifier labeled 'Amp
Control'. I assume the 'Amp Control' is a function of the Band
Selector Button. When the "AM/MW" Band is 'selected' then the "AM/MW
Antenna Pre-Amplifier" is feed power (Turned ON) and the Ferrite Rod
Antenna Signal is feed into the radio.
NOTE: When "AM/MW" Band is "NOT" 'selected' then the "AM/MW Antenna
Pre-Amplifier" is "NOT" feed power (Turned OFF) and the Ferrite Rod
Antenna Signal is "NOT" feed into the radio.
.
Concept for the GS800M AM/MW Antenna Modification:
I have always thought that a simple 1/8" 'mono' Jack (Normally Closed
Type).
Could be inserted into the circuit between the "Ferrite Rod Antenna"
and the "AM/MW Antenna Pre-Amplifier".
* Normally, the 'internal' Ferrite Rod would be connected into the
circuit; since an External AM/MW Antenna is "NOT" connected via this
1/8" 'mono' Jack.
* However, when an External AM/MW Antenna was connected via this 1/8"
'mono' Jack; the 'internal' Ferrite Rod would be disconnected from the
circuit; and the External AM/MW Antenna is connected into the circuit.
.
The Next Question then becomes: What Type of 'External AM/MW Antenna
to Use?
* Simple small AM/MW Loop like a Select-A-Tenna 541-M, Terk and
RadioShack?
* Larger Box AM/MW Loop 2-4 Foot
* Larger 'external' Ferrite Rod (200mm by 10mm) with 'X' Turns of
evenly spaced wire over its full length?
NOTE the GS800M's internal Ferrite Rod is only 100mm by 7mm, and it is
covered with evenly spaced wire over its full length. This is
supposedly a very broad band MW & LW ferrite rod antenna
configuration; vice some tightly wrapped wires all place at one end of
the ferrite rod only.
.
Does Anyone have Any Ideas on how to measure the GS800M's internal
Ferrite Rod's impedance and resonant frequency?
.
Does Anyone "Know How To" Wrap a 'larger' 200mm by 10mm Ferrite Rod
with 'X' Turns of evenly spaced wire over its full length, to match
the GS800M's internal Ferrite Rod's impedance and resonant frequency?
.
This is a Link to the RF & IF Block Diagram in the 'Photo' Section of
the Grundig Satellit 800 Millennium Yahoo eGroup.
http://photos.groups.yahoo.com/group/satellit800/vwp?.dir=/&.src=gr&.dnm=RF+%26+IF+Block+Diagram+GS800M.jpg&.view=t&.done=http%3a//photos.groups.yahoo.com/group/satellit800/lst%3f%26.dir=/%26.src=gr%26.view=t
.
~ RHF
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phil :)
i am having surprisingly good luck with the $20 Rat Shack loop... it's well
made and comes with a jack and wire to connect to high impedance inputs.
btw, Radio Plus has a $15 gizmo (link below) that couples loop output to a
portable... thus bypassing any attenuation or filtering before the internal
ferrite rod. i don't own a Sat800 so ask someone with one if it will work.
http://www.dx-tools.com/QCoupler.htm
phil :)
Keith
I use the Radio Plus Quantum QX Pro Loop with the Sat 800 (attached to
the 50ohm coax in the back) and it works great. I actually use this
setup for Domestic MW DX (rather than the Drake R8A..which I use mainly
for TA MW dx; LW dx; and Ute SW dxng). I also own the KIWA Loop and
while I feel the Kiwa has tighter nulls the Quantum seems to have a
little more gain....IMHO.
Keith
Gary
with my Satellit 800 with excellent results.
I have found the Terk to make a BIG difference on the lower end of the
MW dial when the radio is using the AC power supply, and a BIG
difference on the entire MW band when using batteries. I get good
daytime reception from several MW stations in San Francisco, about 200
miles from where I live.
RHF
I have already used the GS800M with the following 'external' AM/MW
Loop Antennas:
* RadioShack AM Loop
* Terk AM Loop
* Select-A-Tenna 541-M
* Torus Tuner 27" MW Loop
* Quantum Pro 15" QX Loop
+ 3 'home made' MW Box Loops
There all worked very good and the Torus and Quantum were super.
But what I am interest in is a 'external' MW (200mm Ferrite Rod)
Antenna that could be raotated; to act as a set top 'plug-in'
replacement for the fixed 'internal' "mini" MW (100mm Ferrite Rod)
Antenna.
Some other commentators in the past have said the GS800M's 'internal'
"mini" MW (100mm Ferrite Rod) Antenna is a two coil tuned circuit that
is part of the GS800M's MW Pre-Amplifier Circuit.
? Now Is That True?
? Anyone have the actual 'schematic' diagram for this 'internal'
"mini" MW (100mm Ferrite Rod) Antenna and Pre-Amplifier?
? So, does that mean that the 'external' set top 'rotatable' MW (200mm
Ferrite Rod) Antenna would have to have two coils to interface into
the pre-amp to make the MW circuit work? {Maybe use a 1/8" Stereo
Phone Plug for the 'connection' like the Quantum & Palomar loop heads.
The GS800M is basically 'too big' to rotate easily. The internal MW
Antenna (100mm Ferrite Rod) Antenna does an OK job. I think an
replacement 'external' MW Antenna (200mm Ferrite Rod) Antenna would do
a Super job for MW DXing with the GS800M.
Possibly there is a commercial product here and I should be sending
this question to RadioPlus, Palomar and Kiwa for their consideration?
~ RHF
= = = garya...@aol.com (Gary) wrote in message news:<fc4afcdc.02091...@posting.google.com>...
radiok3pi
like it might be what you are after.
Russ
> But what I am interest in is a 'external' MW (200mm Ferrite Rod)
> Antenna that could be raotated; to act as a set top 'plug-in'
> replacement for the fixed 'internal' "mini" MW (100mm Ferrite Rod)
> Antenna.
>
RHF
Sounds good, but I already have the Q-Stick Plus from GT. Actually I
have one each of GT’s MW DXing Products and the are all
exceptionally well designed and offer superior performance for what
they do.
* Here is a Free Promo, go to GT’s RadioPlus+ website
(www.dx-tools.com) check out his products; they are Very Good.
* While you are there take the time to VOTE
(www.dx-tools.com/BestDXrx.htm) for your best/favorite AM/MW DXing
Radio/Receiver.
But my idea (Challenge) is to build a bigger replacement ferrite rod
antenna for the GS800M.
* Length: 200mm vice 100mm
* Diameter: 10mm vice 6mm
* Rotatable vice fixed.
* Plug-in for Dxing and Un-Plug for Normal Operation.
* Use the GS800m’s internal MW Pre-Amplifier.
Buy may be you are right and I should contact GT at RadioPlus+.
His Quantum QX Loop Head: If Modified would be basically what I want.
* Modify the top of the GS800M case above the speaker with a 1/4"
stereo jack.
* Plug-In one of his Loop Heads that has been modified to 'mimic' the
GS800M’s internal MW ferrite rod antenna.
* The Loop Head would use the GS800M’s internal Pre-Amplifer.
* Rotate the Loop Head for best Peak of Null as needed.
VOILA - We have a DX Signal !
Question is... Would GT accept the Tasking?
Is there a ‘commercial’ market for this special GS800M
Loop Head?
~ RHF
= = = k3...@arrl.net (radiok3pi) wrote in message news:<53da5b99.02091...@posting.google.com>...