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Old 2-Nov-2018, 8:33 PM   #9
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,452
TWO Defective RCA TVPRAMP1 Preamps

My first RCA TVPRAMP1R preamp had these measurements:
Voltage out of power inserter without preamp: 19.5 VDC
Voltage with preamp connected: 9.5 VDC
Load current: 70 mADC
Gain 23 db

I thought it was strange that the voltage out with no load was so high because the power inserter contains a voltage regulator, but it worked.

Recent measurements of first TVPRAMP1R:
No load voltage: 13.5 VDC
Voltage under load: 7.37 VDC
Load current: 18 mADC
Gain: 0 dB; Uh-Oh!

Second (new) TVPRAMP1E measurements:
No load voltage: 9.11 VDC
Voltage to preamp under load: 9.11 VDC
Load current: 75 mADC

well, that looked good so far, but
Gain: 5 dB; not so good

I thought there was something wrong with my signal level meter, so I substituted a CM7777HD at low gain:
Gain: 17 dB; right where it should be.

My meter is OK, the RCA preamp isn't OK.

I can't recommend the RCA TVPRAMP1 preamp.
If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 2-Nov-2018 at 9:58 PM.
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