[time-nuts] Ventilation of HP 58503A GPS time & frequency reference receiver

Tom Van Baak tvb at LeapSecond.com
Mon Dec 15 02:11:34 EST 2014

Hi Dave,

There are several variations of 58503A, 58503B, 59551A, etc. Not to mention all the Z38 variations of the basic HP SmartClock technology. Please do not bother HP, Agilent, Symmetricom, or Microsemi. At this point I have more vintage gear and way more historical and forensic interest in the past than they do.

I will take this up with you off-list, as this thread/topic is now getting rather off-topic. List -- if something useful comes from all of this, David or I will surely post a single, informative follow-up note in the coming days or weeks. Meanwhile, let's close this thread.

  ----- Original Message ----- 
  From: Dr. David Kirkby (Kirkby Microwave Ltd) 
  To: Discussion of precise time and frequency measurement ; Tom Van Baak 
  Sent: Sunday, December 14, 2014 10:38 PM
  Subject: Re: [time-nuts] Ventilation of HP 58503A GPS time & frequency reference receiver

  On 15 Dec 2014 00:52, "Tom Van Baak" <tvb at leapsecond.com> wrote:
  > If any of you want me to post more photos let me know. I have several of every kind of HP/Agilent GPSDO product. And they are all genuine because I bought them a decade before the China/eBay/GPSDO business.

  Hi Tom,
  I would appreciate some pictures of a 85053B that is

  * mains powered
  * Does not have the keypad/display

  if you have one.

  I appreciate given the options on this instrument, you might not have one with the exact same configuration as mine. 

  Ideally pictures of the front,  back, sides & bottom.

  I was intending dropping Symmetricon an email in the hope that they could help. If they had an HP one it would be really useful.  

  I am weary of believing any photo I currently see on the web to be honest. Someone said 90% are likely to be genuine,  but I am not so sure that is true.

  I rather suspect a lot of dealers have fakes, but are unaware of it.

  I notice that the keypad & display were available as an upgrade,  suggesting that the case would not need extra ventilation,  so the case should be the same, but eBay may be less convinced. Likewise I doubt a different case would be used for AC and DC models, but eBay might be less convinced. 


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