Description
New pair of 7189 tubes made by RCA in USA.
Detailed description
The 7189 is a power pentode that is designed to withstand higher plate voltages then a regular EL84 (or 6BQ5) (400V vs 300V). Except for the higher accepted plate voltage the parameters of this tube are identical to the EL84.The tube can be used in equipment where an EL84 pentode is required but not the other way round.
Amplifiers like Sansui AU70 and AU-500 or Pioneer SX-82 and SX-800A or Fisher X-101 do require this tube type and cannot properly operate with a regular EL84.
Both tubes are thoroughly tested and have excellent test values (note test results below).
Test method
Mutual transconductance, plate current, gas and shorts tested with: AVO CT-160 (Dutch army tester), Utracer3+, Philips 1532, RFT stabilised power supply and 2x Keithley 2700. Test conditions: Anode 250V, Screen 250V, Grid -7.3V, Filament 6,3V, Rated Ia = 48mA, Gm = 11,3 mA/V. AVO Valve Data Manual 23rd edition 1981 Before testing the tubes were burned in for 48 hours.
Test results*
The measurement data below show that the tubes test NOS and are matched (< 5%).
| Valve
V48 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
61 mA
12,9 mA/V OK |
NOS
NOS
|
| Valve
V49 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
57 mA
12,6 mA/V OK |
NOS
NOS
|
Summarized description
| Tube type | 7189 |
| Quantity of Tubes | One pair |
| Brand | RCA |
| Manufactured in | USA |
| Date code | DU |
| Plate Construction | Round grey plate construction |
| Getter Construction | Disk getter |
| Print Condition | See pictures |
| Box included | Original RCA boxes |
| Equivalent tubes: | E84L |
| General test results | NOS |
Ask any questions before bidding. Thank you.
