AUDIO and TELEPHONE LINE ATTENUATORS
Our Audio Attenuators are a Square Pad, which puts resistance across the pair as well as in-series with the pair, to maintain a 600 ohm impedance.
Our Telephone Line Attenuators have resistance in-series with the pair, since you can't put resistance across a telephone line.
RJ11 1 Pair SQUARE PAD ATTENUATOR
RJ11 Modular Fixed Value Square Pad Audio AttenuatorMade to order from 1 to 40db, for a 600 ohm line impedance.
Connects in-series with a modular line cord, on the middle pins of the jack.
Optimized for both voltage-driven (like from an op amp) and impedance-driven (like from a transmission line), to provide the most accurate attenuation in either case.
The low impedance error ensures accuracy when two or more Square-Pads are hooked in series to make another value. (Like 10 dB + 3 dB to make 13 dB.)
Part Number: DSI6S Price: $22.50 ||| 3+ Price: $20.50
RJ45 1 Pair SQUARE PAD ATTENUATOR
Same as above, but with RJ45 jack and cord.
Connects in-series with an 8 pin modular line cord, on the middle two pins of the jack.
Made to order from 1 to 40db, for a 600 ohm line impedance.
Part Number: DSI6T Price: $24.50 ||| 3+ Price: $22.50
66 BLOCK 1 Pair SQUARE PAD ATTENUATOR
Same as above, but fits on a 66M block (won't fit on a 66B block, which has different pin spacing).
Made to order from 1 to 40db, for a 600 ohm line impedance.
Part Number: DSI6R Price: $24.50 ||| 3+ Price: $22.50
1 to 4db Loss Insertion (Attenuation) TesterThere are times when you have to reduce the audio level of a telephone line.
High audio levels can lead to Touch Tone (DTMF) recognition problems, echo, and distorted sound.
The Loss Insertion Tester will let you insert 1 to 4db of loss into the line, to let you see if reducing the volume on the line will fix your problem.
Temporarily install the Loss Insertion Tester in-series between the telephone line or analog station port, and the telephone equipment. By pressing the two switches, you can insert 1, 2, 3 or 4db of loss into the pair.
There are two components to a telephone line. The DC talk battery, and the AC audio. Other devices like our Loop Current Regulator and Loop Current Attenuator only affect the DC voltage and loop current of the phone line. They're specifically made NOT to lower the AC audio on the line, since that would cause Can't Hear problems as you lowered the loop current.
The Loss Insertion Tester and Fixed Value Attenuators reduce both the DC voltage and the AC audio on the line (even though you probably only want to lower the AC audio level with these devices).
By putting a Modular 4db Fixed Attenuator (not included) in-series with the Loss Insertion Tester, you can insert 5, 6, 7 or 8db of loss into the pair when you push the switches.
It's unlikely you'll need to insert more than 8db of loss onto a regular phone line. For each 1db of loss you insert, it reduces the loop current on the line by about 1ma.
If you insert too much loss, and bring the loop current below 23ma, you'll create other problems on the line like cut-offs, answering and dialing problems. You should be watching the loop current on your meter or Loop Current Tester as you attenuate the line, to make sure you don't go below 23ma.
NOTE: Don't put in more than 1 or 2db of loss in-front of a VoIP system with the Loss Insertion Tester. Putting too much loss in the line can make an impedance mismatch worse, creating echo (rather than fixing it). It will only take a minute or two to see if a little attenuation will help echo problems on a VoIP phone system or line.
We have both Modular and 66 Block versions
of our Fixed Attenuators (below)Part Number: CID9I Price: $34.95
Modular Telephone Line Fixed Value AttenuatorsThere are times when you have to reduce the audio level of a telephone line.
Our Modular Fixed Value Attenuators come in 1, 2, 3, 4, 6 and 8db values. They are very useful for reducing echo on a phone line or station port.
The loop current will drop by about 1ma for every 1db of attenuation you add to the line.
You can cascade the Modular Fixed Value Attenuators in-series with each other to add attenuation. A 1db Attenuator and 8db Attenuator would give you a total of 9db of attenuation.
If you insert too much loss, and bring the loop current below 23ma, you'll create other problems on the line like cut-offs, answering and dialing problems. You should be watching the loop current on your meter or Loop Current Tester as you attenuate the line, to make sure you don't go below 23ma.
MODULAR 1db ATTENUATOR
One pair passes through Attenuator (RJ-11).
Part Number: CID9J Price: $18.95 ||| 3+ Price: $16.95
MODULAR 2db ATTENUATOR
One pair passes through Attenuator (RJ-11).
Part Number: CID9K Price: $18.95 ||| 3+ Price: $16.95
MODULAR 3db ATTENUATOR
One pair passes through Attenuator (RJ-11).
Part Number: CID9L Price: $18.95 ||| 3+ Price: $16.95
MODULAR 4db ATTENUATOR
One pair passes through Attenuator (RJ-11).
Part Number: CID9M Price: $18.95 ||| 3+ Price: $16.95
MODULAR 6db ATTENUATOR
One pair passes through Attenuator (RJ-11).
Part Number: CID9N Price: $18.95 ||| 3+ Price: $16.95
MODULAR 8db ATTENUATOR
One pair passes through Attenuator (RJ-11).
Part Number: CID9O Price: $18.95 ||| 3+ Price: $16.95
66 Type Telephone Line Fixed Value AttenuatorsThere are times when you have to reduce the audio level of a telephone line.
Our 66 Block Fixed Value Attenuators come in 1, 2, 3, 4, 6 and 8db values. They are very useful for reducing echo on a phone line or station port.
They're made to be used on a split 66M block (66M1-50). They won't fit on a 66B block.
Connects in-series between the telephone line or analog station port on the left side of the 66 Block, and the telephone equipment on the right side of the 66 Block.
The loop current will drop by about 1ma for every 1db of attenuation you add to the line.
If you insert too much loss, and bring the loop current below 23ma, you'll create other problems on the line like cut-offs, answering and dialing problems. You should be watching the loop current on your meter or Loop Current Tester as you attenuate the line, to make sure you don't go below 23ma.
66 BLOCK 1db ATTENUATOR
Only fits on a split 66M block.
Part Number: CID9C Price: $18.95 ||| 3+ Price: $16.95
66 BLOCK 2db ATTENUATOR
Only fits on a split 66M block.
Part Number: CID9D Price: $18.95 ||| 3+ Price: $16.95
66 BLOCK 3db ATTENUATOR
Only fits on a split 66M block.
Part Number: CID9E Price: $18.95 ||| 3+ Price: $16.95
66 BLOCK 4db ATTENUATOR
Only fits on a split 66M block.
Part Number: CID9F Price: $18.95 ||| 3+ Price: $16.95
66 BLOCK 6db ATTENUATOR
Only fits on a split 66M block.
Part Number: CID9G Price: $18.95 ||| 3+ Price: $16.95
66 BLOCK 8db ATTENUATOR
Only fits on a split 66M block.
Part Number: CID9H Price: $18.95 ||| 3+ Price: $16.95
90A Attenuator (AT&T / Lucent / Avaya)
Comcode 107864456. Recommended by Avaya. Comes with D4BU 2 foot cord for proper polarity.
Part Number: MMA1Q Price: $19.95 ||| 3+ Price: $18.90 ||| 10+ Price: $17.90
Modular Half REN Line Terminator™Simulates a telephone with .5 REN on the line.
The Modular Half REN Box™ terminates a telephone line or analog station port at voice frequencies, changing the impedance of the line.
Changing the impedance of the line can correct quite a few problems:
- DTMF Recognition Problems
- Volume Problems
- Distortion Problems
- Echo Problems
The Half REN Box™ has proven to be very valuable for fixing voice mail and faxback DTMF and CNG tone recognition problems!
Connects in-series with a modular jack and plug, between the telephone line or analog station port, and the telephone equipment.
Keep some in your case!
Part Number: CID9A Price: $18.95 ||| 3+ Price: $16.95
66 Type Half REN Line Terminator™Simulates a telephone with .5 REN on the line.
The 66 Type Half REN Box™ terminates a telephone line or analog station port at voice frequencies, changing the impedance of the line.
Changing the impedance of the line can correct quite a few problems:
- DTMF Recognition Problems
- Volume Problems
- Distortion Problems
- Echo Problems
The Half REN Box™ has proven to be very valuable for fixing voice mail and faxback DTMF and CNG tone recognition problems!
They're made to be used on a split 66M block (66M1-50). They won't fit on a 66B block.
Connects in-series between the telephone line or analog station port on the left side of the 66 Block, and the telephone equipment on the right side of the 66 Block.
Keep some in your case!
Part Number: CID9B Price: $18.95 ||| 3+ Price: $16.95
These resistors are rated to take the kind of current you'll see on a phone line. Regular 1/4 and 1/2 watt resistors may burn up.
They must be used in pairs, one on the tip and one on the ring, when wired in-series (keeps the line balanced).
Generally speaking, the loop current will drop by about 1ma, and the level of the line will go down by around 1db for every 100 ohms you put in-series with the tip and ring.
Keep some in your case!
100 Ohm 2W Resistor (Bag of 10)
Bag of 10
Part Number: SER8A Price: $1.69
200 Ohm 2W Resistor (Bag of 10)
Bag of 10
Part Number: SER8B Price: $1.69
120 Ohm 5W Resistor
Sold Individually
Part Number: SER8C Price: $1.39
These capacitors are rated to take the ring voltage on a phone line (90-100VAC). More common 50V capacitors may burn up.
Capacitors are used to block DC voltage. The most common use for capacitors in Telephony is in the ringing circuit, where they are always in-series with the ringer or bell.
Without a capacitor in series with a bell, when the phone rang the line would be tripped (or would stay off hook all of the time). The capacitor allows the AC ring voltage to pass through to the bell, while blocking the DC voltage which would take the line off-hook.
Another common usage for capacitors is getting audio off of a line with talk battery. If you put a line with talk battery into an amplifier or recorder, the DC voltage will probably look like foreign voltage to the device - and it won't sound too hot. Putting a .47 or 1mf cap in-series with one side of the line going to the amp will block the DC and just pass the audio (which is AC).
Keep in mind that if the line rings, it may blow up the amp or recorder! Ring voltage is AC, just like audio.
You do not have to put capacitors in series with both sides of the line feeding the amp (or whatever), since there is no DC path to become imbalanced (the cap blocks the DC). You wouldn't want to run an audio pair a long distance after the capacitor.
Keep some of these in your case!
.47mf 100V Capacitor
Sold individually
Part Number: SER9H Price: $0.89
1.0mf 100V Capacitor
Sold individually
Part Number: SER9I Price: $1.99
They must be used in pairs, one on the tip to ground, and one on the ring to ground.
These will work well for lower frequencies like AM, but will have little or no effect on FM. Using capacitors to drain the RF to ground can cause other problems on the line, because of increased capacitance.
Keep some in your case!
.01mf 100V Capacitor
Bag of 10
Part Number: SER9F Price: $1.69
.02mf 100V Capacitor
Bag of 10
Part Number: SER9G Price: $1.69
630-980-7710
Copyright © 2011 Mike Sandman Enterprises, Inc.
