[R-390] R389 and R390 faults

[Mark Huss]

Opps, Caught by the R-390/R-390A confusion again!
About the BFO Counter knob.  Your right, it is not a vernier knob.  But 
someone in the history of mine must have replaced the shaft extension 
with a 3:1 vernier reduction gear.  Very handy.

Barry Hauser wrote:

> Hi Mark, Rob
>
> Not sure what comes first logically, but here goes:
>
> First -- the R-390A Y2K manual on my website is the original, not 
> revised version.  If that's what you need, suggest you go to Al 
> Tirevold's site for the later version.
>
> Second -- Rob is asking primarily about the R-389 & R-390 (without the 
> A) --  apparently, as the '389 is related to the '390, not the A. The 
> Y2K manual on my website and Al's is strictly for the R-390A.
>
> I am not that familiar with the R-389, but if the power supply and AF 
> deck -- which is mostly power supply/regulation components is the 
> same, same applies to both:  The 6082's throw a lot of heat.  The AF 
> deck is mounted upside down so the heat rises and tends to cook the 
> components under the chassis.  In particular, it is recommended to 
> replace the 47 ohm resistors (4 of them I think) as per Dave Medley's 
> advice.  In addition, it's a good idea to use a small fan set up to 
> exhaust the heat from that side of the mainframe. R-390/URR's -- the 
> pre-cost reduced edition -- do not exhibit the same capacitor failure 
> patterns as the R-390A/URR's.  Component and tube compliment are very 
> different.
>
> AS for the counter knob on the BFO, they are not vernier/gear 
> reduction drives, just counters which were added to improve 
> reset-ability of the BFO -- unless someone also added a 10-1 reduction 
> drive as well, but it's not part of the counter-knob mechanism.
>
> hope this helps,
> Barry
>
>
>
> ----- Original Message ----- From: "Mark Huss" <mhuss1 at bellatlantic.net>
> To: "Rob Filby" <robsr390a at btopenworld.com>
> Cc: <R-390 at mailman.qth.net>
> Sent: Tuesday, March 21, 2006 2:02 PM
> Subject: Re: [R-390] R389 and R390 faults
>
>
>> First, you may want to reference the R-390A manual at 
>> http://www.hausernet.com/r390a/
>> It should have everything you need.  Pay particular attention to the 
>> Capacitor replacement listing.  AWlso, for some reason, 2.2K 
>> resistors in the R-390A's seem to change value considerably.  
>> Otherwise, just watch the list.  Good Luck.
>>
>> The counter knob on the BFO was added to R-390A's used for RTTY 
>> reception. Makes tuning the BFO to FSK tones much easier.
>> Rob Filby wrote:
>>
>>> Hi.
>>>     I have recently bought an R389 and a pair of R390 rxs. They are 
>>> all complete and in good condition.
>>> At first appearance it seems as the PSU, Audio stage and IF strip 
>>> are interchangable. I have a few questions which I would to ask the 
>>> group and perhaps somebody could help me please.
>>>
>>> 1.Were any parts listings produced for the above rxs, ie detailing 
>>> the wattage of resistors and the voltage
>>> ratings of other components?
>>>
>>> 2.Are there any common faults or other troublesome components that 
>>> fail or give trouble that I need to be
>>> aware of?
>>>
>>> 3. I have a couple of R390A rxs which have a mechanical counter for 
>>> the BFO, why was this used over the standard knob?
>>>
>>> Thanks for your help
>>>
>>> Rob.  _____________________________________________________________
>>> R-390 mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/r-390
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>>>
>>>
>>
>>
>> -- 
>> More women than men believe in ghosts, while more men than women 
>> believe in UFOs. This proves that men will believe almost anything if 
>> it comes with really great gadgetry.-- Captain Ed --
>>
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>
>
>


-- 
More women than men believe in ghosts, while more men than women believe in UFOs. This proves that men will believe almost anything if it comes with really great gadgetry.-- Captain Ed --