Two strategies to improve Sangean ATS-909X sensitivity

ATS-909XSWLing Post contributor, Moshe, writes:

“I would like to share something I noticed about Sangean sensitivity issue:
As I own the ATS909, I noticed that with fresh set of regular batteries (1.5V) or it’s power transformer, it is very sensitive.
When the voltage of the batteries drops, so does sensitivity! Which means that if one uses rechargeable batteries (1.2V), the radio will be much less sensitive to begin with.”

Many thanks, Moshe! That is a very good reason to keep fresh alkaline batteries for the 909X, or to run it on a quiet power supply. Moshe is correct–fresh rechargeable batteries can’t deliver full voltage.

Several weeks ago, a reader informed me about a modification that increases SW sensitivity by adding a 4:1 impedance transformer.

Click here to download a PDF that documents the 4:1 transformer procedure.

Note that I can’t remember who shared the PDF and am not sure who was so kind to document the procedure with photos. Any additional information would be appreciated.

Have any readers performed the transformer mod on the ‘909X with success?

Modify An Icom IC-735 To Work DRM

The original IC-735 brochure.  Click to enlarge.

The original IC-735 brochure. Click to enlarge.

Are you a ham radio operator and/or SWLer that would like to dabble in DRM (Digital Radio Mondial) but don’t have a purpose-built  receiver? A friend recently brought to my attention a clearly-outlined DIY photo instructional for a modification you can make to the classic Icom IC-735 ham transceiver to add a 12 Hz downconverter and I.F. output jack.

If you’re handy with a soldering iron, view the PDF instructional created by Matthias Bopp (DD1US) for making this modification. The downconverter (along with many other DRM items) is sold by German firm, SAT-Schneider–follow this link to purchase it online for just 25 Euros.

logo_drmThough the IC-735 is primarily a ham radio transceiver, it has general coverage and makes for an exceptional shortwave broadcast receiver as well.  In fact, I have an IC-735 in my shack and use it primarily for SWLing. This unit was produced by Icom in the 1980’s; many are available now in the used market for around $325-450US. A great value for the money, especially if you also happen to be a ham.