[R-390] 17.000 Mhz Crystal

[Norman Ryan]

Hi, all,

I wonder if oven temperature is critical to crystal performance (other than limiting frequency drift).  Oftentimes a heater will fail due to corroded leads from the pin(s) to the heater element.

Is a working oven heater element an issue, given that most of our receivers are operated in generally stable ambient temperatures?  That is, would a failed heater element put a harelip on performance?

73 de Norman, KG4SWM


--- On Mon, 5/13/13, Roger Ruszkowski <flowertime01 at wmconnect.com> wrote:

> From: Roger Ruszkowski <flowertime01 at wmconnect.com>
> Subject: Re: [R-390] 17.000 Mhz Crystal
> To: R-390 at mailman.qth.net
> Date: Monday, May 13, 2013, 9:05 PM
> 
> Gordon,
> 
> Yes you can swap the first mixer crystal with the second
> mixer crystal 
> just to check that the second mixer crystal is the problem
> on
> 14 and 31.
> 
> I have no idea how far off frequency it will be.
> 
> You may get lucky and it will work very well.
> 
> Back when we just had two many parts on hand and
> never had to resort to this level of maintenance.
> 
> I always had 400 plus receivers in the building and more
> than
> one of them was not in exact use a any given hour. I could
> always find an exact part to swap. 
> 
> As this is a rebuild, look for some crud in a socket pin.
> a shorted trim cap wire. But first just plug in a different
> crystal.
> 
> Thunk the crystal a time of two as it may have crud inside.
> 
> Crystals do go bad and is the most likely problem.
> 
> Just resetting the crystal a time of two in the socket may
> clean
> up the contacts.
> 
> If you have a scope, you do not need an exact crystal.
> 
> Swap any crystal within reason 15 - 20 Mhz into the
> socket and look for a signal with the scope on the RF
> mixer tube pin. 
> 
> Roger AI4NI
> 
> 
> 
> 
> 
> Well, I finally have my R-390A re-assembled.
> I turned it on today and so far looks and works great EXCEPT
> for 14 and 
> 31 Mhz.
> After some quick checks, it appears my 17.000 Mhz (Y-412)
> Crystal is bad.
> Does anyone have one to sell ?
> 
> Thanks,
> Gordon
> N6WK
> 
> 
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> 
> 
> -----Original Message-----
> From: Gordon <gordon at n6wk.com>
> To: R-390 <R-390 at mailman.qth.net>
> Sent: Sun, May 12, 2013 7:54 pm
> Subject: [R-390] 17.000 Mhz Crystal
> 
> 
> Well, I finally have my R-390A re-assembled.
> I turned it on today and so far looks and works great EXCEPT
> for 14 and 
> 31 Mhz.
> After some quick checks, it appears my 17.000 Mhz (Y-412)
> Crystal is bad.
> Does anyone have one to sell ?
> 
> Thanks,
> Gordon
> N6WK
> 
> 
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> 
>  
> ______________________________________________________________
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