Audio & Interstage Transformers - Hermetically Sealed
High Impedance - 1,001 Ohms & Up
Click here for Audio & Interstage Transformers - Hermetically Sealed - Low Impedance
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Audio Matching Transformer
Source Impedance: 200 - 700 ohms
(TM) TM003
Sennheiser audio matching transformer. Source impedance: 200 - 700 ohms. Load impedance >= 5k ohms. 1:15 ratio. Frequency resistance: 30 - 20,000 Hz. 3/4"D x 1"H. Fits 1/4"D hole.
 

Impedance Matching Transformer
800 ohms Output Z
(TM) LM9003
Vintage input impedance matching transformer. Used primarily in RTS/Telex intercom matching networks. 800 ohms output Z. 3/4" x 5/8" x 5/8"H. Sold in matched pairs only.
$35 each
 
$18 per pair

Audio Transformer
150 Ohm / 2.75v / 300 - 6000 Hz / 0.05 watts

(TA) L284441-1
Bendix audio transformer. Hermetically sealed. Hook terminals. NSN: 5950-645-5383

• Primary: 25k c.t. @ 0.01 amp
• Output: 150 ohm, 2.75v, 300 - 6000 Hz,
0.05 watts, 1 terminal, #2 terminal case
• Dimensions: 7/8"D x 1"H
 

Audio Transformer
62 Ohm DCR - 1500 Ohm Input / Output

(TA) 6771600000
JB audio transformer. Dual primary & secondary. Two channel. Hermetically sealed, electro-statically shielded. Mfg. P/N: 124P287. NSN: 5950-00-228-0805.

• 100 - 5000 Hz, 62 ohms DCR
• 100 ma / 30 watt capacity
• Input / Output: 1500 ohms
• Frequency Resistance: -1.0 / 1.0 dB
• Dimensions: 4.438" x 3.656" x 4.359"H
$22 each - $20 (6+)
 
$150 each

Audio Transformer
250 Ohm ct / 600 Ohm ct

(TA) 224-2M
ADC mil-grade audio transformer. Balanced 600 ohm output. Blue epoxy case.

• 60 Hz - 10k Hz, 82 ma, 0.25w, 175wv
• Dimensions: 1-1/16"sq x 7/8"H
 

Audio Transformer
1500 ohm : 1500 ohm - 10 mw
(TA) 150-B-1133
Audio transformer. 1500 ohm : 1500 ohm, 10 wv. Hermetically sealed. NSN: 5950-845-2297.
$24 each - $21 (3+)
 
$18 each

Transformer
2500 ohm : 250 ohm
(TA) 27404
Freed transformer. 40 ma. 2500 ohm : 250 ohm. 500v, 1.5 watts. 1-3/8" x 1-3/8" x 2". Loral P/N: 450-2046.
NSN: 5950-00-646-5039.
 

Audio Transformer
600 Ohm : 3k Ohm

(TA) 33114
Freed mil-grade audio transformer.

• 600 ohm primary with shield to dual 1500 ohm (3,000 ohm total) secondary.
• 0.5 dB 0.3 - 3 KHz
• Dimensions: 1-7/16" diameter x 2"H
$18 each
 
$45 each - $39 (3+), $35 (10+)

Altec Lansing Plate Coupling
Primary Z = 3300 ohm c.t.
Secondary A = 250 / 500 ohm

(TA) TMJ-217A
Altec Lansing scrumptious audio coupling transformer. Sealed. Bottom terminals. New. 26 available.

• Frequency Response: 15 KHz
• Primary Z: 3300 ohm CT
• Secondary A: 250 / 500 ohm
• Dimensions: 4-1/4" x 4-3/8" x 5-1/8"H
 

Lionel Plate Coupling
Primary Z = 3.5k ohm c.t.
Secondary A = 125 ohm

(TM) CU-66/UR
Lionel Corporation Grade 1 Class A plate coupling transformer. Sealed. Made in 1945 for US Army Signal Corps by Lionel, the model train manufacturer turned military supplier.

• 10 watts
• Primary Z: 3.5k ohm CT
• Secondary A: 125 ohm
• Dimensions: 2"sq x 2-1/2"H + terminals
$129 each - $117 (3+)
 
$25 each - $21 (3+), $18 (10+)

Output Transformer
200 - 3500 ohm Frequency Response

(TA) 186B
Western Electric output transformer. 200 - 3500 ohms frequency response. Made in 1968. NSN: 5950-235-6758.

• Input: 175 ohms (terms 1-2),
107 ohms DCR, 1.2 Hy
• Output: To 30,000 ohms (terms, 3-4, 5-6),
4850 DCR
• Dimensions: 1-5/8" x 3" x 4"H
 

Collins Transformer,
as removed
1,500 ohms : 3,750 ohms / 75w

(COL) 672-2300-00
Collins, CTC audio transformer has lots of miles left. Sealed, bottom terminals, flanges. 2 pc. available.

• 1,500 ohms : 3,750 ohms / 75w
• 100 - 5,000 Hz, ±1 dB
• Ratio: 1 : 1.59
• 3 kv high pot
• Dimensions: 4" x 4-1/2" x 5-1/2"H
$95 each
 
$125 each
 

Mini Molded PC Mount
Audio Transformer

(TA) MMT11M
Microtran audio transformer.

• 4000 ohm CT: 600 ohm CT
• 5 madc, 28 dBm
• 200 Hz - 15 KHz
• 175 wv to ground
• Dimensions: 3/4" x 7/8" x 1/2"H
 
 
$10 each - $9 (3+), $8 (10+)
 

Collins Transformer,
as removed
6,000 ohms : 6,000 ohms c.t. / 20w
 

(COL) 677-2010-00
Collins, CTC audio transformer has lots of miles left. Sealed, bottom terminals, flanges. 2 pc. available.

• 6,000 ohms : 6,000 ohms c.t. / 20w
• 200 - 5,000 Hz, ±1 dB
• Ratio: 1 : 1
• 3 kv high pot
• Dimensions: 2-3/4" x 2-5/8" x 3-3/8"H
 

Audio Transformer
280wv @ 0.001 adc

(TA) 1752
Precision Electronics 2 watt audio interstage transformer.

• 7.5k ohm : 200 ohm
• 280wv, 0.001 adc
• Dimensions: 1-1/4" square x 1-3/4"H
$95 each
 
$24 each - $21 (6+)

Freed Coupling Transformer
2500 ohm CT Nominal @ 50 ma

(TA) 31002
Freed coupling transformer. Hermetically sealed, electro-statically shielded. Working volts to ground = 800v. Level = 12 watts. Removed from new equipment.

• Primary: 8000 ohm ct nominal @ 50 ma
• Secondary: 2500 ohm ct nominal @ 50 ma
• Dimensions: 2-7/8" x 3" x 5"H
 

Audio Transformer
DCR = 30 ohm / 1.5 watts / 18.5 ma
  Bottom view

(TA) F25426-1
Audio transformer. DCR = 30 ohm, 1.5 watts, 18.5 ma.
NSN: 5950-00-645-1856.

• Primary: 9000 ohm
• Secondary: 5000 ohm
• Dimensions: 3.5" x 2.75" x 3.5"H
$89 each
 
$35 each

Audio Transformer
4k / 5k c.t. to 8k / 10k c.t.

(TA) DO-T52
UTC miniature audio transformer. Electrostatic shield. Does not have threaded base.

• 4k / 5k CT to 8k / 10k CT
• NSN: 5950-00-837-5497
 

Audio Frequency Transformer
10k c.t. to 25 ohm
(TA) 75263
UTC audio frequency transformer. 10k C.T. to 25 ohm. 10 watts. 1:20 ratio. Hermetically sealed. 1-1/2"D x 2-3/8"H. NSN: 5950-231-4763.
$12 each - $10 (3+), $9 (10+)
 
$75 each

Pico Audio Transformer
9k / 10k : 9k / 10k @ 1 ma

(TA) LB225
TRW Pico audio transformer. 105ºC. NSN: 5950-00-449-1742.

• 9k / 10k : 9k / 10k @ 1 ma, 100 mw
• Dimensions: 0.335"D x 0.475"H
 

Audio Transformer
Pri: 9k ohms, 0.027a / Sec: 3.2 ohms, 0 madc

(TA) M1407
Atlantic Transformer Corp. audio transformer. (Looks like UTC). 2 watts. Electrostatically shielded. Hermetically sealed. Corner posts 1.25" c-c. NSN: 5950-00-615-4876. Beautiful!!

• Primary: 9k ohms, 0.027 amps
• Secondary: 3.2 ohms, 0 madc
• Dimensions: 1.5" x 1.5" x 2-1/4"H
$18 each
 
$69 each
 

Pico Audio Transformer
10k c.t. to 2k Split
(TA) M27/172-35
TRW Pico interstage audio transformer. 300 ohm to 10 KHz. 10k center tapped to 2k split. 100 mw, 1 ma, 105ºC. 0.337" diameter x 0.469" high. Collins P/N: 677-1521-000.
 
 
$15 each - $13.50 (6+)
 

Audio Transformer
Primary: 14k
Secondary: 35k, 11 KHz

(TA) TA56
Audio transformer. Hermetically sealed. 2 : 1 ratio. Turret terminals and posts on bottom. NSN: 5950-00-648-5705.

• Primary: 14k
• Secondary: 35k, 11 KHz
• Dimensions: 1-1/8" x 1-5/8" x 2-1/4"H
 

Audio Transformer
Primary: 15k ohms @ 4 madc
Secondary: 4 terminals - 95k ohms Split

(TA) S-6506
UTC audio transformer. Round. Hermetically sealed. Hook terminals. 1.175" c-c ears. NSN: 5950-016-4444.

• Primary: 15k ohms @ 4 madc
• Secondary: 4 terminals - 95k ohms split,
200 - 10,000 Hz, +11 dBM, 175 pk wv
• Dimensions: 7/8"D x 1-3/8"H
$35 each
 
$47 each

Audio Transformer
15k : 95k c.t.

(TA) H5
TRW / UTC audio transformer. Round, hermetically sealed. 15k : 95k c.t., 50 Hz - 10 kHz. 30 mw, 175 wv. 0.953" dia. x 1.34" high. Alt. P/N: TF4R21YY M27/166-17.
 

Freed Matching Transformer
165 ohm, 200 ma, 80 watts

(TA) 31001
Freed matching transformer. 200 ma. Level = 80 watts. Hermetically sealed. Working volts to ground = 1,100v. Made for 811A circuit. Removed from new, boxed equipment.

• Primary: 18,000 ct
• Secondary: 165 ohm
• Dimensions: 5" x 4" x 6-1/4"H
$45 each
 
$165 each

Thordarson Plate Coupling
Primary Z = 18k ohm c.t. (5300 vrms)
Secondary A = 125 ohm (1500 vrms)

(TA) T56626
Thordarson Grade 1 Class A plate coupling audio transformer. Sealed. Bottom terminals.

• Frequency Response: 175 watts 500 CPS to 6 KHz
• Primary Z: 18k ohm CT (5300 vrms)
• Secondary A: 125 ohm (1500 vrms)
• Dimensions: 3-3/4"D x 4-1/2"H
 

Audio Transformer
600 / 600 ohm

(COL) 677-0425-00
Chicago Transformer audio transformer. Hermetically sealed. Rounded corners. Terminals & posts on bottom. 200 - 20,000 Hz I2DB, 265 pwv. NSN: 5950-00-645-0737.

• Primary: 20k c.t., 100mw, 10 ma Balanced
• Secondary: 600 / 600 ohm
• Dimensions: 1.515" x 1.515" x 2.14"H
$109 each
 
$59 each - $52 (3+)

Audio Transformer
12k Ohms / 10 watts

(TA) T3
Langevin Mfg. audio transformer. Terminals & posts on bottom. Sealed. Made in 1952. NSN: 5950-647-7053.

• Primary: 4000 ohms @ 0.05 amp
• Secondary: 12k ohms, 10 watts
• 1200 - 3000 Hz
• Dimensions: 2-1/4" x 3" x 2-1/4"H
 

Audio Output
20k ohm @ 5 ma / 600 ohm / 500v
 

(TA) T101
Freed 17042 audio output.

• 20k ohm @ 5 ma
• 600 ohm, 500v
• 3 dB, 50 - 12 kHz
• Dimensions: 2"D x 2-1/4"H
$24 each
 
$39 each

Audio Transformer
10k : 60k / 150 - 4500 Hz / 0.5 watt
(TA) L284341-1
Bendix audio transformer. 10k : 60k. 150 - 4500 Hz. 0.5 watt. Hermetically sealed. 0.875" square x 2.5" high. Made in 1954. NSN: 5950-645-0716.
 

Plate to Grid Audio Transformer
60k / 500v

(TA) O-4
UTC plate to grid audio transformer. 30 - 20,000 Hz. "Ouncer" Alt. P/N: 910033.

• Primary: 15k
• Secondary: 60k, 500v
• Dimensions: 7/8" x 1-1/8"H
$39 each - $35 (3+)
 
$24 each

Audio Transformer
74 / 10 volts / 20 ma
 

(TA) L-382521
Westinghouse audio transformer. 74 / 10 volts, 20 ma. Turns ratio 1 : 3-13/16. 200 - 3000 Hz. 2" diameter x 2.75" high. Made in 1967. NSN: 5950-00-647-7680.

NOTE: You will need a 2" capacitor mounting clamp. (CMH) CLAMP-2. Click here.
 

Audio Input Transformer
Pri: 500 ohms w/tap @ 200 ohms / Sec: 50k ohms

(TA) 467737
ITC audio input transformer. Hermetically sealed. Turret post terminals. 500 vrms. 0.1 watt, 0.1 - 15 kc. NSN: 5950-645-1933.

• Primary: 500 ohms with tap 200 ohms
• Secondary: 50k ohms
• Dimensions: 1.3" x 1.6" x 1.6"H
$25 each
 
$49 each

UTC Audio Transformer
50k Ohms

(TA) 92157
UTC audio transformer. Hermetically sealed. Electrostatically shielded brought out to terminal. New, military surplus from the 1950s. NSN: 5950-227-7791.

• Primary: 50 ohms
• Secondary: 50k ohms, 50 Hz - 10 KHz
• Ratio: 1 : 31-6/10
• Dimensions: 1-3/4"D x 2-1/2"H
 

Audio Transformer
100,000 ohms

(TA) T-1935
UTC audio transformer. Electro-statically shielded. Hermetically sealed. 200 - 500 Hz, 0.06 watt, 150 wv. NSN: 5950-00-328-9795.

• Primary: 75 / 150 ohms
• Secondary: 100,000 ohms
• Dimensions: 1-7/8" x 1-7/8" x 2-1/2"H
$75 each
 
$67 each

Microphone Adapter &
Audio Transformer
100,000 ohms

(MIC) 57A120D1
Microphone adapter and Freed audio transformer. 300 - 20,000 ohms. Includes shield box plus 4 pin flange mount female jack (MS3102A14S) mating with 4 pin inline male (MS3106A14S). New surplus. NSN: 5821-591-3786.

• Primary: 82 ohms, 50 ma
• Secondary: 100,000 ohms
• Dimensions: 2-1/8" x 2-3/4" x 1-5/8"H
 

Audio Transformer
120,000 ohms C.T.

(TA) GAI-7203
Audio transformer. 400 - 3000 cps. Hermetically sealed, electrostatically shielded. Gold turret terminals. NSN: 5950-00-647-5943.

• Primary: 600 ohms C.T. @ 30 ma
• Secondary: 120,000 ohms C.T., 18 dBM
• Dimensions: 1.5" x 1.26" x 2.4"H
$65 each
 
$48 each

Audio Transformer
120k ohm c.t. / 60 Hz / 10 KHz

(TA) 14795
Freed dual primary audio transformer.
NSN: 5950-00-647-6026.

• Primary 1: 333 ohm / 500 ohm
• Primary 2: 50 ohm / 125 ohm
• Secondary: 120k ohm CT, 60 Hz - 10 KHz
• Ratio: 1 : 15-1/2
• Dimensions: 2-5/8" x 2-1/4" x 3"H
 

Centroid Inc. Audio Input
Primary Z = 300 / 600 ohm c.t.
Secondary A = 250,000 ohm
 

(TA) 81175-501
Centroid Inc. audio input transformer. Sealed. Bottom terminals.

• 5 watts max
• Frequency Response: 50 CPS to 10 KHz
• Primary Z: 300 / 600 ohm CT
• Secondary A: 250,000 ohm
• Dimensions: 3-1/4"D x 4"H
*** SOLD OUT ***
 
 
$109 each - $99 (3+)
 
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