Re: [IRCA] [ultralightdx] Re: [ABDX] Question: Which Analog Sony SRF Walkman Would You Rate the Best ULR?

[d1028gary@xxxxxxx]

Hello Steve, Dennis and Mark,
 
<<<   I remember a post by Gary DeBock that identified six AM/FM Walkman radios that utilized the CXA1129N "radio-on-a-chip" ...

 1. SRF-29
 2. SRF-39
 3. SRF-39FP
 4. SRF-49
 5. SRF-59
 6. SRF-S84   >>>
 
Yes, all of these Sony analog "Walkman" portables share the innovative CXA1129N chip (which provides superior sensitivity, selectivity and image rejection on the MW frequencies, compared to most analog pocket radios), and they all share the same basic circuitry. After performing alignments on all of them and observing their build quality, DXing performance and survivability over the past 6 years, however, some important differences have become apparent.
 
As for the SRF-59, it is Sony's mass-produced "economy model," where various quality control corners seem to have been cut in an effort to maximize profits. The factory AM alignments tend to be haphazard at best, with over 80% of the models receiving a major AM sensitivity boost when both the low and high band peaking adjustments are carefully performed by a qualified hobbyist. The quality of the tuning capacitor is low, and the model typically develops the "Scratchy Tuner" issue (noisy static when the MW frequency is changed) after about 2 years of steady usage. The only cure for this issue is complete replacement of the tuning capacitor-- an impractical solution for an $18 radio. Because of the internal CXA1129N chip a well-aligned SRF-59 can provide some serious DXing fun for about 2 years before it goes on the blink, though-- not bad for an investment of around $18.
 
All of the other models listed above (except for the sub-miniature SRF-S84, which has a unique tuner) have a higher quality tuning capacitor than that used in the SRF-59, and as such, all of them should provide good DXing performance indefinitely if they are not abused. Sony also seemed more motivated to provide quality factory AM alignments on these other models, so that most of the SRF-29, SRF-39, SRF-39FP and SRF-49 models are at least "in the ball park" for peak AM sensitivity when they come out of the Chinese factories. The SRF-S84 model is kind of a special case-- around 2011 Sony changed the design of the model so that the AM loopstick coil could not be adjusted, thereby making a low-band AM sensitivity peaking adjustment impossible. As such, new SRF-S84 models typically are relatively deaf on the lower AM frequencies-- a congenital defect that cannot be corrected.
 
As for survivability, the SRF-39FP "Prison Radio" has an awesome reputation of survival in one of the toughest environments on the planet-- among prisoners in high-security jails. As detailed in the special article in the New Yorker magazine recently (  http://www.newyorker.com/online/blogs/elements/2014/01/the-ipod-of-prison-sony-radio.html?currentPage=all  ), the radio is practically indestructible, and is frequently passed down from one convict to another when jail time is over. The SRF-39FP seems impervious to being dropped, and typically comes out of the Chinese factories in excellent alignment. But there is no reason why the SRF-29, SRF-39 and SRF-49 models cannot survive just as long as the SRF-39FP, so long as DXers handle them with care.  

73 and Good DX,
Gary DeBock (in Puyallup, WA, USA)

            



-----Original Message-----
From: R. Mark Barnett <orgelkraft@xxxxxxxxx>
To: ultralightdx <ultralightdx@xxxxxxxxxxxxxxx>; ABDX <ABDX@xxxxxxxxxxxxxxx>
Cc: irca@hard-core-dx com <irca@xxxxxxxxxxxxxxxx>
Sent: Fri, Feb 28, 2014 10:08 pm
Subject: Re: [ultralightdx] Re: [ABDX] Question: Which Analog Sony SRF Walkman Would You Rate the Best ULR?


 
  
    
                  

I have the black SRF-39 and it works well. How is the clear prison model different? I always assumed they were identical inside.  I don't see much difference between MY SRF-39 and the SRF-59s I bought about a year ago... they seem very much the same. The build quality seems better on the SRF-39, but that is a subjective judgement. I don't know how much the newer SRF-59 models vary radio to radio off the production line, but mine are pretty identical... and they work great.

 

Mark B. N8PGV
 

Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality.
~ Nikola Tesla



  
 
 
 
   From: Dennis Gibson <wb6tnb@xxxxxxxxx>
 To: "ABDX@xxxxxxxxxxxxxxx" <ABDX@xxxxxxxxxxxxxxx> 
Cc: "ultralightdx@yahoogroups com" <ultralightdx@xxxxxxxxxxxxxxx>; ABDX <ABDX@xxxxxxxxxxxxxxx>; "irca@hard-core-dx com" <irca@xxxxxxxxxxxxxxxx> 
 Sent: Saturday, March 1, 2014 12:07 AM
 Subject: [ultralightdx] Re: [ABDX] Question: Which Analog Sony SRF Walkman Would You Rate the Best ULR?
  
 


 
     
                  

The AM section died in many of the SRF-59s sold around the time the Ultralight Group got started. Mine did. I still use it for FM. Gary can tell you why. I don't remember.

I think he says the SRF-39FP, the cool looking clear For Prison radio, is the best. I have an SRF-49 and the 39FP is better. It's certainly unique. 

Sent from my iPhone

On Feb 28, 2014, at 8:53 PM, "Stephen H. Ponder" <stephen_ponder@xxxxxxxxxxxxx> wrote:



      
                  
This may seem to be a "Duh!" question to some in the group, but I'm curious as to which of the various analog Sony SRF AM/FM Walkman radios would be considered the "best."

I remember a post by Gary DeBock that identified six AM/FM Walkman radios that utilized the CXA1129N "radio-on-a-chip" ...

1. SRF-29
2. SRF-39
3. SRF-39FP
4. SRF-49
5. SRF-59
6. SRF-S84

I have the SRF-59 and have to say that it is a hot radio for its size. I've been pleasantly surprised by its sensitivity and selectivity, especially here in Houston, TX.

My question is based on the fact that I don't have any other model with which to compare the performance of my SRF-59.

I just ordered an SRF-29 on eBay tonight, based solely on Gary's email about it containing the CXA1129N chip.

Is there a document or spreadsheet somewhere that compares the six radios listed above?

Thanks for your help!!

73 & Good DX,

Steve Ponder, N5WBI
Houston, TX

"Character is not what people see from a distance-- that's platform. Character is more often seen up close and over time." - Ed Stetzer
_____________________
Sent from my Kindle Fire HD 8.9

    
         

    
     



 
 
 
   

    
             
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