RadioBanter

RadioBanter (https://www.radiobanter.com/)
-   Shortwave (https://www.radiobanter.com/shortwave/)
-   -   stormwise monster ferrite - worth it? (https://www.radiobanter.com/shortwave/150322-stormwise-monster-ferrite-worth.html)

DougC March 16th 10 04:38 PM

stormwise monster ferrite - worth it?
 
I want something simple to make.
I'm thinking of better antenna(s) for the RCA superradio and a couple
portable SW radios I have {-the RCA gets stations just fine, it mainly
needs fine-tuning help-}.

I did make a simple passive tuned loop for the SW out of a single turn
of copper grounding rod and a AM radio tuner cap. Worked much better
than the included antennas, but was 4 ft wide and not built real sturdy.

If I do loops I want these to be smaller, maybe 1.5 or 2ft across so I
can move them around and use them indoors easily.

There is also the 13.5" stormwise monster ferrite sticks. They would be
more compact than a loop, but for a small MW/SW recieving antenna, are
these going to receive significantly better?
~


Wimpie[_2_] March 16th 10 09:28 PM

stormwise monster ferrite - worth it?
 
On 16 mar, 17:38, DougC wrote:
I want something simple to make.
I'm thinking of better antenna(s) for the RCA superradio and a couple
portable SW radios I have {-the RCA gets stations just fine, it mainly
needs fine-tuning help-}.

I did make a simple passive tuned loop for the SW out of a single turn
of copper grounding rod and a AM radio tuner cap. Worked much better
than the included antennas, but was 4 ft wide and not built real sturdy.

If I do loops I want these to be smaller, maybe 1.5 or 2ft across so I
can move them around and use them indoors easily.

There is also the 13.5" stormwise monster ferrite sticks. They would be
more compact than a loop, but for a small MW/SW recieving antenna, are
these going to receive significantly better?
~


Hello Doug,

A ferrite of about 13" will not perform better then a well designed
1.5 .. 2 ft diameter loop.

As long as you can get the loop into resonance and include some
matching (inductive coupling loop or coupling with a ferrite core),
noise will very likely be dominated by external noise (instead of
receiver noise).

When you experience that noise from the antenna is far above the
receiver's noise floor, you can reduce the size of the loop.

Instead of reducing the size of the loop, you may increase the
coupling between the receiver and the loop. This will reduce both
signal and noise output, but increases the bandwidth somewhat, so
tuning is easier.

Good luck with the experiments!

Wim
PA3DJS
www.tetech.nl
without abc, the address is valid.

[email protected] March 17th 10 10:19 PM

stormwise monster ferrite - worth it?
 
On Tue, 16 Mar 2010 11:38:10 -0500, DougC
wrote:

I want something simple to make.
I'm thinking of better antenna(s) for the RCA superradio and a couple
portable SW radios I have {-the RCA gets stations just fine, it mainly
needs fine-tuning help-}.

I did make a simple passive tuned loop for the SW out of a single turn
of copper grounding rod and a AM radio tuner cap. Worked much better
than the included antennas, but was 4 ft wide and not built real sturdy.

If I do loops I want these to be smaller, maybe 1.5 or 2ft across so I
can move them around and use them indoors easily.

There is also the 13.5" stormwise monster ferrite sticks. They would be
more compact than a loop, but for a small MW/SW recieving antenna, are
these going to receive significantly better?
~

There is a good article by Dallas Lankford at
http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf
comparing 6in., 1ft, and 2ft air core loops and a space magnet
(ferrite core loop antenna).

I built a couple of loops. The one I kept is a 3 ft with 12 turns #12
across a dual 466pF (932pF var.capacitor) and 1 turn #12 for a pickup
loop with 10 feet of RG58 coax giving a range of 400kHz to around
3.5MHz. I built it so it can be tilted but have never seen much
benefit in doing that. FYI - I used #12 only because I had 1000 ft
sitting in the garage.

Jim


All times are GMT +1. The time now is 08:25 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com