[Hammarlund] AADE Digital display for SP-600 WORKS!

Tue Aug 30 15:33:20 EDT 2005

Eugene, 	

Every now and then I receive an e-mail telling me about this, and similar
products, with an inquiry wondering about making it work for blind Hams, such as
I. Because of the association of Braille and the Blind, the conversion of a
digital display into a tactile readout is generally suggested.  	

Unfortunately, although this is possible with today's technology, the cost is
very high. Making it impractical and generally not affordable.	

Although there are Braille printers, they cost several thousand for the low end
model to above ten thousand for better ones. Only about half of those who are
blind read Braille. those with Diabetes, for example, have reduced touch
sensitivity in their fingers. Making it difficult, or not possible, for them to
feel the six dots that comprise the Braille cell. The sad part about the
technology that could make the lives of the handicapped easier, more productive
and give them a good deal of independence, is that due to a very narrow market,
prices are high to generate a profit. Being as the majority of the handicapped
live at or below the national poverty level, they can not afford these wonderful
aids. the majority of the sales go to the government, colleges, rehab agencies,
some primary and secondary school systems, big businesses and so forth. 	

I thought that when technology was able to drop the production cost of the
synthetic speech chips and associated software and hardware, that we would see
the development of many new devices at affordable prices. Unfortunately, and to
my surprise, the exact opposite happened. The only devices built were cross
market products, that is, for the sighted or normal hearing or not in a
wheelchair etc. If the handicapped benefited, it was secondary. Hence, such
products as the talking calculator vanished because it was no longer being
purchased by the non-handicapped population. Mine is by Sharp and from 1982. It
is very basic and not that great to start with, awkward design, hard to use. But
it still serves a purpose. When it fails, that is that.	

Fortunately for me, I generally use an Abacus, so I will get by fine. However, I
am the exception and not the rule, so those who do not, are going to have to go
without.	

Regarding the output of this digital display being modified for voice output,
once again, absolutely doable. parts are not expensive at all. But the
technology to develop such devices is not profitable, hence it won't happen.
While it all seems wrong to me, it is the way that business works.	

Duane W8DBF	

----------
From: Eugene Hertz <ehertz at tcaf.org>
To: Philip Atchley <beaconeer at sbcglobal.net>; hammarlund at mailman.qth.net
Subject: Re: [Hammarlund] AADE Digital display for SP-600 WORKS!
Date: Tuesday, August 30, 2005 1:32 PM

I have a special version of the DFD-hamm. I found a source of VFD (vacuum
florescent displays) that are pin for pin compatible with the LCDs that neil
uses.  He bought a few and made me one. Now my DFD is BEAUTIFUL! blue VFD.
Easily seen in darkness. There were one or two small mods he had to make to get
it to work (something about noise from the onboard dc-dc converter).

I highly recommend asking him about this option.  If I can I will try to post a
picture of the unit tonight.

Next project for me is to use nixies!

Eugene

>-----Original Message-----
>From: Philip Atchley [mailto:beaconeer at sbcglobal.net]
>Sent: Tuesday, August 30, 2005 12:20 PM
>To: hammarlund at mailman.qth.net
>Subject: [Hammarlund] AADE Digital display for SP-600 WORKS!
>
>Hi All, 
> 
>Well, after a number of hours of working on it, I got this little 
>critter to work properly. As I mentioned in an earlier Email, I'd tried 
>tapping the LO at both the grid and the plate connection., Finally I 
>made a "gimmick capacitor" off the lead going to the FCU switch, to feed 
>my Source Follower "Isolation amplifier", but STILL had problems. Last 
>night I even put a small pot on the BNC connector input of the unit so I 
>could adjust the level. 
> 
>This confirmed ONE thing. I had plenty of signal, at least on the low 
>bands. That because if I turned it up all the way it would read a 900kc 
>tuned frequency as over 2MC (apparently the 2nd harmonic of the LO). 
>Turning it down about halfway and the three lower bands worked PERFECTLY! 
> 
>HOWEVER, the readings were still very erratic on the three higher bands. 
> I could often make it read anything I wanted from the "real" frequency 
>to about +/- 15-20kc. Not what I would call a stable circuit. 
> 
>THEN, this morning I removed the "tweak" jumper from the display board 
>and things settled down to a nice steady reading of exactly what it 
>should be!! That "tweak" jumper activates two small, 25turn pots that 
>allow you to "tweak" the unit to allow for Xtal Filter errors and a 
>second LO Xtal that is off frequency. 
> 
>NOW, it reads correctly, but is about 200Hz off on BOTH the low and high 
>bands, this probably due to a drifted Xtal filter. I CAN LIVE WITH 
>200CPS ERROR! 
> 
>So far it appears to be working exactly as it should, with no 
>instabilities, but time will tell. 
> 
>One other thing I noticed is that it no longer reads up to 53MC (it's 
>specked to 40MC). I 'might' be able to get it to read higher by 
>adjusting the input pot, but I'm going to leave well enough alone ;-) 
> 
> 
>73 de Phil KO6BB 
>My DXing tools (RECEIVERS), all fully overhauled: 
> Hammarlund SP-600 R-274C/FRR, 18 tubes (Circa 1952) 
> National NC-60 Special, 5 tubes (Circa 1960) 
> Heathkit Mohican (Circa 1962) 
> Icom IC-751 Digital Transceiver (Circa 1986) 
> Grundig S350 Digital Portable (Circa 2004) 
> 
>THE BEACONEER'S LAIR: http://www.geocities.com/ko6bb/ 
>QSL GALLERY: http://photobucket.com/albums/y123/KO6BB/ 
>Merced, Central California, 37.3N 120.48W CM97sh 
> 
>****************************************************** 
> 
> 
>_______________________________________________ 
>List Administrator: Duane Fischer W8DBF 
>** For Assistance: dfischer at usol.com ** 
>---- 
>http://mailman.qth.net/mailman/listinfo/hammarlund 
>

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