eHam.net - Amateur Radio (Ham Radio) Community

Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net


Reviews Categories | Filters, RF: bandpass, duplexer, lowpass, highpass, RFI/EMI, e | Alden McDuffie CW filter Help


Reviews Summary for Alden McDuffie CW filter
Alden McDuffie CW filter Reviews: 1 Average rating: 5.0/5 MSRP: $62.90 kit; $72.90 assembled
Description: A 500 Hz outboard filter powered by internal 9-volt battery or external 12-volt supply.
Product is in production.
More info: http://www.aldenmcduffie.com
Email Subscription
You are not subscribed to this review.

Subscribe!
My Subscriptions
Subscriptions Help

You can write your own review of the Alden McDuffie CW filter.

KC0MAX Rating: 5/5 Dec 19, 2004 20:38 Send this review to a friend
Fun and useful kit  Time owned: 3 to 6 months
The Alden McDuffie 500 Hz CW outboard filter goes between the radio and your headphones and does a great job, at about half the price of the Icom CW filters. It is a great companion to radios such as the Icom 703 and works very well, particularly with use of the 703's IF shift. It also has the advantage of being able to be used with other radios, and is particularly suited for field use, because it is powered by an internal 9-volt battery (or 13.8 volt external supply). The filter is an 8-pole Chebyshev, 500 Hz bandwidth, centered at 750 Hz. The battery draws just 10 ma with no signal, and ~ 12 ma with average signal. There is also an audio pass-through.

The filter does a great job of filtering out noise and competing signals. My experience has been that peak audio response on this filter is around 850 or 900 Hz. Also, the audio output is mono, so a pair of headphones that has a mono/stereo switch and perhaps a volume control will enhance one's listening enjoyment. I found that the very inexpensive Coby DV-130 phones, which have both of these features, is an outstanding value at less than $6 at Big Lots.

While many argue that outboard filters do not compare to IF filters, the AM filter is certainly convenient, and I use it every day. I also have friends who have had good luck with it. The kit takes about an hour or so to build, the manual is clear, and the case is well-made and very professional. The filter was designed by Phil Anderson, W0XI, who does terrific work and provides outstanding support. This was the first Alden McDuffie kit I built, and I have ordered several more since. The manual for the filter and other AM products is available for download from the Alden McDuffie website.

Max KC0MAX
 


If you have any questions, problems, or suggestions about Reviews, please email your Reviews Manager.