[Premium-Rx] Sherwood SE-3

[Llgpt at aol.com]

I can attest to both units, I currently use a Kiwa map unit connected to my 
rebuilt R-274C/FRR (SP-600JX-14) and feed the 455 if output of the Map (post 
filtering) to the Sherwood SE-3. Great audio spectacular filters, using the 8 
kc (yes, kc, I'm old) and the narrowband on the Map, I can listen to ssb with 
spectacular audio. I have used this combination with a R-390A, and many other 
receivers over the years, including another SP-600 and fed a Hammarlund 
SPC-10 ssb adapter with great results. I have owned two Map Units over the 
years, s/n 32 and 92, I can echo Guy's comments, he wrote a great review in 
the 1989 Fine Tunings Proceedings which led to my first Map purchase.

Les Locklear

In a message dated 4/4/2003 1:43:09 PM Central Standard Time, 
dx at guyatkins.com writes:

> Another external synchro-AM detection box to keep an eye out for is the Kiwa
> "MAP" (Multiband AM Pickup). It is a competitor to the SE-3 from the early
> ninties, but in my opinion it offers comparable performance with more
> features and sturdier, more attractive construction. It was one of Kiwa
> Electronics' first products, and Craig Siegenthaler over-designed it
> physically (rounded-corner custom cabinet w/40+ case screws, high grade
> powdercoat paint, etc.) so that it ended up too expensive to sell
> profitably. The MAP's owners manual is a thing of beauty, with full
> schematics, specs &information which rivals the best receiver manuals.
> 
> Features beyond synchro-AM detection in the MAP include dual bandwidths
> (cascaded ceramics similar to Kiwa's current Filter Modules) that 
> supplement
> the receiver's own filters depending on the IF "pick-off" point"; a true
> tone tilt control a la audiophile stereo gear; a tunable audio filter; 455
> IF signal output &recording outputs; and a carefully-chosen internal
> speaker matched to the enclosure (Craig tested lots of manufacturer's
> samples before settling on a speaker). All front panel switching on the MAP
> is done with soft-touch FET-controlled pushbuttons. The MAP uses either a
> direct IF pickup either pre- or post- receiver filtering or to the product
> detector in some receivers, or an indirect pickup using an IF "sniffer" 
> coil
> (recommended for any receiver with a DC voltage higher than 50v at the
> pickup point).
> 
> Craig had his production MAP tested by the Hatfield &Dawson engineering
> group of Seattle, to verify the performance specs. Each MAP included a
> "Certificate of Performance with specific figures for each unit. Among 
> other
> data, mine shows the following:
> 
> Wideband filter response: +/- 2.0dB 50 Hz-3.0 kHz "OK"
> -6dB point: 3.23 kHz
> -60dB point: 4.27 kHz
> Shape Factor -60/-6dB: 1.32
> Ultimate Rejection at 6 kHz: -101 dB
> 
> The figures for the narrow bandwidth include a measured -6dB point of 1.47
> kHz, and measured ultimate rejection of -108dB.
> 
> These bandwidths make for some useful additional selectiity when cascaded
> with the receiver's own filters.
> 
> I recall one particular session with the MAP in 1991 or 1992. During a 
> March
> WA coastal DXpedition at Grayland, we monitored for minimum discernable
> signal on 1566 kHz (HLAZ, Chenju, S. Korea). A JRC NRD-525 lost audio and
> then eventually the het at 2 hours past local sunrise. However, switching 
> in
> the MAP restored weak audio when the signal was only a het with the NRD
> alone. The het was finally lost on the 525/MAP combo an amazing 3 hours 
> past
> local sunrise.
> 
> The Kiwa MAP was only manufactured until 1992, but occasionally one shows 
> up
> on the used market. They were made extremely durable, so unless one has 
> been
> abused it should still perform very well. My current Kiwa MAP was recently
> acquired as NOS, new in the box from Craig when he moved his business to
> Minnesota. Evidently it is the last MAP made... serial #109.
> 
> Craig's plans for a "MAP II" never materialized, unfortunately. He had
> planned rework the mechanical aspects to make it more profitable to 
> produce,
> and add a second, PLL-type synchronous detector for the user to choose 
> from.
> 
> BTW, the MAP was reviewed by me in-depth for an early edition of the Fine
> Tuning's "Proceedings" series of books; I think it was the 1991 or 1992
> edition.
> 
> 
> Guy Atkins
> dx at guyatkins.com
> Puyallup, WA USA
> 

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