|
Home | Forums | Rules | Articles | diyAudio Store | Blogs | Gallery | Wiki | Register | Donations | FAQ | Calendar | Mark Forums Read |
Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum |
|
Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving |
![]() |
|
Thread Tools |
![]() |
#1 |
diyAudio Member
Join Date: Mar 2019
|
![]()
Hi all,
I am restoring a Raytheon RC10 tube broadcast console from the 1940s. The large (4") Simpson VU meter is not working. I have taken the meter apart, and inside the meter there are two wirewound resistors. The resistor that attaches to the + input terminal is open. I am trying to find out the correct value for this resistor. Can anyone help me? Thank you Tyler |
![]() |
![]() |
#2 |
diyAudio Member
Join Date: Apr 2011
|
This RC-11 manual has some RC-10 info, but only this much on the meter:
VU Meter: 0-1 ma DC Weston Model 862 https://www.steampoweredradio.com/pd...e%20Manual.pdf Since most such meter movements have a basic 50uA sensitivity, you should be able to calculate the value of the bad resistor from the value of the good resistor and the 1mA full scale spec. Last edited by rayma; 24th November 2020 at 02:11 AM. |
![]() |
![]() |
#3 |
diyAudio Member
Join Date: Aug 2006
Location: Taxland, New Jersey
|
These meters have an internal rectifier assembly like all "real" VU meters have. I just happen to have one of these near by. So I opened it and measured both resistors. The one on the right measures 1.099K ohms. So it's safe to call it 1.1K at probably 1%. The other resistor at the top goes across the rectifier and measures 718 ohms in one direction and 2.810K in the other. All values include roughly 3 ohms lead resistance. Hope this helps. (Had I used one of my Agilent DMMs I could have nulled that out, but the B&K DMM was more handy)
__________________
"At the heart of quantum mechanics is a rule that sometimes governs politicians or CEOs - as long as no one is watching, anything goes." ~ Lawrence Krauss Last edited by HollowState; 24th November 2020 at 02:24 AM. |
![]() |
![]() |
#4 |
diyAudio Member
Join Date: Mar 2019
|
Hollow State, thank you very much!!!!
Tyler |
![]() |
![]() |
#5 | |
diyAudio Member
|
Quote:
IIRC, the customary sensitivity was 200uA. (They are not quite as fragile as the 50uA meters found in high-end VOMs.) |
|
![]() |
![]() |
Thread Tools | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Simpson 260 Series 8 Schematic or Repair Manual | dennismiller55 | Equipment & Tools | 3 | 16th February 2013 12:17 AM |
A LED meter, Volt meter, power meter or light indicator... a nice gadget | destroyer X | Solid State | 5 | 25th February 2011 07:30 PM |
Simpson series 5 P meter | Burnedfingers | Equipment & Tools | 1 | 10th August 2006 04:44 PM |
FS: Simpson 260 Vintage VOM | Zero Cool | Swap Meet | 0 | 15th July 2006 07:50 PM |
NICE Simpson 260 series 7 VOM for sale | NotInTheMafia | Swap Meet | 0 | 19th October 2005 07:30 PM |
New To Site? | Need Help? |