Welcome, Guest. Please login or register.
08-25-2019 -- 04:34:38

Login with username, password and session length

Top 10 Posters

flew-da-coup (1303)
Hawaii596 (1015)
USMCPMEL (845)
griff61 (573)
Hoopty (548)
docbyers (544)
MIRCS (535)
CalLabSolutions (517)
PMEL_DEVIL-DOG (509)
Thraxas (498)
Members
  • Total Members: 3657
  • Latest: wilders
Stats
  • Total Posts: 19132
  • Total Topics: 3579
  • Online Today: 54
  • Online Ever: 242
  • (04-19-2014 -- 19:20:34)
Users Online
Users: 0
Guests: 48
Total: 48


Author Topic: E4407B (AN/USM-677) *NEED HELP ASAP*  (Read 2308 times)

Offline PurelyNonsense

  • 5-level
  • ***
  • Posts: 130
  • Action Taken: +1/-0
    • Email
E4407B (AN/USM-677) *NEED HELP ASAP*
« on: 03-20-2018 -- 15:02:04 »
Good morning all,
I'm assisting a tech with a repair on a spectrum analyzer. Since I have little experience on the piece, I wanted to know if anyone has experience repairing these? First off let me let you know what is the issue.
The unit shows that ever signal below approximately 3 GHz is reading up to 20 dBm. So it won't align or even be useful. We tried replacing parts with known good ones. The tech even replaced the RF section to no avail. Replacing the attenuator board helped a little but not enough. Any ideas?

Offline griff61

  • 7-level
  • ****
  • Posts: 573
  • Action Taken: +35/-3
Re: E4407B (AN/USM-677) *NEED HELP ASAP*
« Reply #1 on: 03-20-2018 -- 18:33:57 »
Questions
Is the battery good?
Did you reset the defaults?
Do you have the ability to realign it there or do you need to evac?
Where does the white go when the snow melts?
Sarcasm - Just one more service I offer

Offline PurelyNonsense

  • 5-level
  • ***
  • Posts: 130
  • Action Taken: +1/-0
    • Email
Re: E4407B (AN/USM-677) *NEED HELP ASAP*
« Reply #2 on: 03-26-2018 -- 10:44:00 »
Hey there Griff, we got it. It's the IF section that's bad. Time to order some parts now! And the white goes back to the magic calibration fairies when the snow melts to check the luminosity for the next batch. My question is, do you have real white sands in White Sands? And why is it white? Is the cartel involved?

Offline griff61

  • 7-level
  • ****
  • Posts: 573
  • Action Taken: +35/-3
Re: E4407B (AN/USM-677) *NEED HELP ASAP*
« Reply #3 on: 03-26-2018 -- 15:50:34 »
My question is, do you have real white sands in White Sands? And why is it white? Is the cartel involved?

Not quite that exciting...it's all about the gypsum, but you can toboggan on them and not get wet!
Sarcasm - Just one more service I offer

Offline flew-da-coup

  • 9-level
  • *****
  • Posts: 1303
  • Action Taken: +17/-24
  • Missing in Action
Re: E4407B (AN/USM-677) *NEED HELP ASAP*
« Reply #4 on: 03-27-2018 -- 16:02:25 »
My question is, do you have real white sands in White Sands? And why is it white? Is the cartel involved?

Not quite that exciting...it's all about the gypsum, but you can toboggan on them and not get wet!
Maybe its Pablo Escobar's ashes. Maybe?
You shall do no injustice in judgment, in measurement of length, weight, or volume.Leviticus 19:35

 

DISCLAIMER:  This site is not an official US Air Force site, it is intended for private use only.  It is not endorsed, in any way, by the US Air Force, the DoD, or any other governmental agency.  Additionally, all information found within this site is just that, it is NOT meant to be used in place of authorized publications.


All logos and trademarks in this site are property of their respective owner.

All forum content is the property of the respective poster, all the rest 2004-2017 by PMEL Forum.