[R-390] R389 and R390 faults

[Tom Norris]

No, if you read further down, Rob does ask about the 390A counter knob.

"3. I have a couple of R390A rxs which have a mechanical counter for  
the BFO, why was this used over the standard knob?"

So you gave the correct answer


Tom

On Mar 21, 2006, at 2:04 PM, Mark Huss wrote:

> 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 --
>
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