[Milsurplus] thoughts on the SRR family of radios

Mon May 9 21:54:49 EDT 2016

John said:One other weak spot (of the SRR series) – the input power line filter on the rear panel should be bypassed, as it is connected directly to the line before any fusing. When things go south in the sealed assembly, it can cause a fire and other safety issues in your shack.
This should apply equally to the R-390A (and perhaps other receivers) since the line filter is also before the switch and fuse in this radio too.  
Eliminating the AC line filter allows line noise into the receiver.  Not sure what the effect would be with either the SRR series or the R-390A but I did notice quieter operation of my 310F-6 (a KWT-6 but receive only) when I added one of those computer type line filter units to a 2U blank panel at the top of the rack.  The added filter seemed to get rid of the florescent light line noise.Jim 

      From: "boatanchor at martasystems.com" <boatanchor at martasystems.com>
 To: Military Surplus Mail List <milsurplus at mailman.qth.net> 
 Sent: Monday, May 9, 2016 11:46 AM
 Subject: Re: [Milsurplus] thoughts on the SRR family of radios

#yiv8926838093 #yiv8926838093 -- _filtered #yiv8926838093 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;}#yiv8926838093 #yiv8926838093 p.yiv8926838093MsoNormal, #yiv8926838093 li.yiv8926838093MsoNormal, #yiv8926838093 div.yiv8926838093MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:11.0pt;}#yiv8926838093 a:link, #yiv8926838093 span.yiv8926838093MsoHyperlink {color:blue;text-decoration:underline;}#yiv8926838093 a:visited, #yiv8926838093 span.yiv8926838093MsoHyperlinkFollowed {color:purple;text-decoration:underline;}#yiv8926838093 span.yiv8926838093EmailStyle17 {color:windowtext;}#yiv8926838093 .yiv8926838093MsoChpDefault {} _filtered #yiv8926838093 {margin:1.0in 1.0in 1.0in 1.0in;}#yiv8926838093 div.yiv8926838093WordSection1 {}#yiv8926838093 Great summary, Ray. It’s nice to see there are others who have worked with and appreciate these radios. I’ve had a number of them over the years, and currently own a pair of FRR-23s - same as the SRR-13s, for all practical purposes. I was fortunate to obtain a module tester, the MX-2012/U, which works with a TV-3 tube tester. It accommodates each type of module, and makes life much simpler – the manual for this (and the entire set) is in the “Library” at http://www.mrcgwest.org One other weak spot – the input power line filter on the rear panel should be bypassed, as it is connected directly to the line before any fusing. When things go south in the sealed assembly, it can cause a fire and other safety issues in your shack. BTW, I’ve got a bunch of spare modules for the –11 if anyone needs one. John WB6AZP     From: Ray Fantini Sent: Monday, May 09, 2016 13:24To: Military Surplus Mail List Subject: [Milsurplus] thoughts on the SRR family of radios Additional thought on the SRR-13 family of radios, just to demonstrate that there are at least three people who find them interesting! Over the years I have owned three or four examples and have found them to be fun little radios. Have been told that they were intended to replace the R-390 in fleet operations but due to their lack of stability and the unfortunate period of time that they were designed between the end of the vacuum tube era and the beginning of the solid state era they are little more than a footnote in history. Designed for AM, CW and RTTY the radio has a disadvantage in not including SSB although SSB can be copied it’s obvious that this radio was designed right before the widespread deployment of SSB for most operations. The radio also suffers from a drifting master oscillator in the first detector, at least on the 13 that’s the HF version I have no first hand experience on the LF version the SRR-11 or the mid band SRR-12.  With the exception of one 6X4 tube in the power supply all of the other tubes are of the sub miniature peanut verity and are soldered onto small modules that in theory make maintenance easy but in reality unless you had a set of spare sub-assemblies or a second or part radio were almost impossible to work with. And the biggest problem was the switch arms that were produced from cast meatal that mate with sliding bars between sub-assemblies  that would move the appropriate switch when changing modes or bands and if overtighten would crack and brake and if under tighten would not work the switch.  I had the opportunity of meeting with one of the people who worked on the design back in the old days and he gave me a huge box of parts that included a bunch of steel switch levers that solved the problem along with a huge stock of spare sub-assemblies and the jumper cable that would allow you to operate the receiver outside of its case. This allowed me to keep one working and repair several others around that time back in the late eighties. The radio had an optical display that was fun, relatively good sounding AM and good image rejection. I gave one to a friend to use down in Mexico for a while being he was living next to a couple 50 Kw broadcast stations and most other radios would overloaded and did not work in that environment but the SRR-13 had no issues with the local broadcasters. Although not light is still smaller and lighter than the R-390 and I would also say its more users friendly then the R-390 with its thousand knobs. And despite its habit of braking switch levers would take the relatively simpler mechanical systems of the SRR over the overly complex R-390 any day of the week, but that’s just me. Looking at an SRR-13 you can see the evolutionary process taking place between the old generation of rack mount open frame receivers to the smaller tightly sealed for both environment and EMF/RFI to the next generation of radios like the R-1051, URC-32 and the RT-618, no the designs are not the same but you can see in the case design and the use of modular sub-assemblies the family lineage. I have not owned or used an SRR in maybe twenty years being that I progressed into sold state radios like the General Dynamics R-1051 and other Watkins Johnson receivers but with all this talk about the old SRR family wanted to put this out there.  Question – Back in the seventies and eighties there were a lot of these radios in the Ham fest circuit, I am going to assume that because anywhere that they were deployed in active duty they were quickly replaced by R-1051 receivers and many were deployed thru Navy MARS? Any thoughts?   Ray F/KA3EKH ______________________________________________________________
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