[R-390] R-390A and the SP-600

Wed Feb 14 07:09:11 EST 2018

Was anymore done on this? The message below is the last one I have seen 
on the subject.
Did I have messages bounce and missed it?
Thanks

-- 
73...
Bob de k2ki
k2ki at comcast.net
k2ki.bb at gmail.com (Goes to my cell)
802-752-7225 (Cell - Call anytime)
SKCC #12195
NAQCC #2337

On 1/12/2018 11:08 PM, Alan Victor wrote:
> Thanks for the offer Norm. I'll be away for a couple of days. I'll see what
> is involved in scanning and IF its a big cost deal, I may take you up on
> your offer. It is all single sided, so that makes it a bit easier and the
> pages are standard letter size. Of course, since it came from a micro film
> slide, the printed pages are slightly smaller than letter size.
>
> As a heads up, when I get a chance, I'll type up the TOC and forward.
>
> On Fri, Jan 12, 2018 at 1:24 PM, Norm n3ykf <normanlizeth at gmail.com> wrote:
>
>> Alan,
>>
>> I've got a scanner with an automatic doucment feeder. Happy to scan it
>> if you'd like. Live in Binghamton, NY currently.
>>
>> Usually have the wide pages done at the local print shop. Easier that way.
>>
>> Norm n3ykf
>>
>> On Fri, Jan 12, 2018 at 4:04 PM, Alan Victor <amvictor at ncsu.edu> wrote:
>>> Hi Tim, Bob, others.
>>>
>>> I had several inquires once I fixed the misunderstanding that this is
>> paper
>>> and not film!
>>> Anyway, I brushed the document off and started looking through it again
>>> after many years collecting dust.
>>>
>>> I have been working on an active tuning preselector and there is an
>>> excellent treatment of broadband varactor tuned networks which is worth
>>> posting. That said, I think I will look at the cost of scanning the
>>> document or just scan it myself and send a pdf to the 390a reflector. Not
>>> sure how large a file it would be, but certainly much less than a Y2K
>>> manual! Alan
>>>
>>>
>>> On Fri, Jan 12, 2018 at 12:19 PM, Tim Holzheimer <timholz59 at hotmail.com>
>>> wrote:
>>>
>>>> Alan
>>>>
>>>> I would like a copy of the RADC-TR-67-216 document.
>>>>
>>>> Let me know.
>>>>
>>>> Thank you.
>>>>
>>>> Tim Holzheimer
>>>>
>>>> 73 de N6DIY
>>>>
>>>>
>>>> ------------------------------
>>>> *From:* r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net>
>> on
>>>> behalf of Alan Victor <amvictor at ncsu.edu>
>>>> *Sent:* Thursday, January 11, 2018 2:47 PM
>>>> *To:* Tisha Hayes
>>>> *Cc:* R390A
>>>> *Subject:* Re: [R-390] R-390A and the SP-600
>>>>
>>>> If any interest prior to the land fill or other Earth friendly paths.
>>>> .
>>>> I have an excellent copy from microfiche from the Rome Air Force
>>>> Development Center
>>>>
>>>> *Preferred-circuit Techniques for Receiver Applications*
>>>> Over 1000 pages Tech report no. RADC-TR-67-216.
>>>> Date June 1967.
>>>>
>>>> Covers every conceivable circuit technique at the time for wideband
>>>> receiver techniques; 1 MHz-10 GHz.
>>>>
>>>> Any interest, email me direct. 73' Alan
>>>>
>>>> On Sat, Jan 6, 2018 at 7:16 PM, Tisha Hayes <tisha.hayes at gmail.com>
>> wrote:
>>>>> I have had a chance to compare "a few" receivers. Presently I own;
>>>>>
>>>>> R-390A (three of them so there is some general opinions)
>>>>> R-390
>>>>> R-392
>>>>> SP-200
>>>>> HQ-129
>>>>> SP-600 (JX17)
>>>>> RF-590A (Harris)
>>>>> R-3030 (Cubic)
>>>>> CDR-3250 (Cubic)
>>>>> RA-6790 (Racal, four of them)
>>>>> WJ-8718 (Watkins Johnson)
>>>>> 5650 (Telefunken, three of them)
>>>>>
>>>>> - It may seem like "a bunch" of radios but that is just the premium
>>>> stuff.
>>>>> I have a tendency to chase after perfection. (it may seem weird but I
>> am
>>>>> for-real, ask Perry, he knows me personally). Here is my opinion on
>> the
>>>>> Hammarlund family in comparison to the R-390A;
>>>>>
>>>>> The SP-600 was a fantastic radio that came out when AM and CW were
>> king
>>>>> around 1951. The design is reminiscent of the pinnacle of "knob
>> turner"
>>>>> radios and is a pleasure to use for SWL or BCB-DX listening. The JX17
>> is
>>>>> really not the "best model" of the receiver, it was designed to
>> support
>>>>> diversity pairing with another radio and some changes in the circuitry
>>>> and
>>>>> voltages were made. If the crystal filter is close to the IF
>> frequency it
>>>>> can be a decent radio but often the crystals have changed frequency or
>>>> the
>>>>> radio was mis-tuned somewhere along the line. It also has a big
>> problem
>>>>> with BBOD (black beauty of death) oil caps and the electrolytic (the
>> cans
>>>>> and the bathtubs) capacitors.
>>>>>
>>>>> I have tried a bunch of things on an SP-600. Taking B+ ripple down to
>> the
>>>>> single millivolt level with filtering changes, building the "Nuvistor
>>>> first
>>>>> RF" plug-in instead of a 6BA6 and fighting (the never ending) battle
>>>>> against drive slippage between the frequency disk and the knob
>>>>>
>>>>> The SP-600 is "drifty" for the first few hours and it is definitely
>> not
>>>>> frequency stabilized but if you leave it on for a long night of
>> listening
>>>>> to SWL it is a pleasing radio to listen to. The sound is very full and
>>>>> sometimes I just listen to AM-BCB at night for the background noise
>> while
>>>>> doing something else in the house. As has been said it is a pretty
>>>>> "intuitive" radio except for the IF bandwidth that can be a little
>>>>> confusing unless you read up on it first.
>>>>>
>>>>> -----------------------
>>>>> The R-390A is almost a generation newer than the SP-600 and is meant
>> to
>>>> get
>>>>> on a frequency and stay there. Probably more than a few people on this
>>>> list
>>>>> spent their times wearing green or tan, wearing boots and eating
>>>> K-rations
>>>>> while they maintained racks full of R-390's in RTTY service. It works
>>>> great
>>>>> for data, is not as deaf as the SP-600 at higher frequencies and can
>> be
>>>>> passably good with SSB with an external converter.
>>>>>
>>>>> The R-390A is not a knob spinner (we all know that) and I invested
>>>>> significant time in to smoothing out the drive mechanisms, playing
>> with
>>>>> synthetic oils and tungsten disulphide to make it less straining on
>> the
>>>>> wrists. It has a better tube line-up in the RF deck and the advantages
>>>> (and
>>>>> disadvantages) of mechanical IF filters. I have added roofing filters
>>>>> between the RF and the IF and rather than butchering the audio deck I
>>>> just
>>>>> pick off the audio and feed it in to the AUX input on a Telefunken
>> 5650
>>>>> receiver (fantastic audio quality).
>>>>>
>>>>> By itself the R-390A can be "tiring" to listen to all evening long. It
>>>> has
>>>>> a hard to describe "robotic" sound. One receiver does not have that
>>>> effect
>>>>> but it is a rare R-390A variant with ceramic filters in the IF.
>>>>>
>>>>> How I wish the R-390A had an SSB mode.. it might be another reason
>> from
>>>>> keeping me away from the Harris RF-590A that I have been increasingly
>>>> using
>>>>> for dial hunting to listen to the chatter on the geritol-net on 80
>>>> meters.
>>>>> -----------------------
>>>>> In the past six months or so I have been buried in Telefunken rebuilds
>>>> and
>>>>> while I read the postings on this list I do not contribute as much as
>> in
>>>>> the past.
>>>>>
>>>>> *Ms. Tisha Hayes*
>>>>> *AA4HA*
>>>>>
>>>>> *Sr. Engineer, 4RF USA.*
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>>>>>
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