Over-modulation is evidenced by clipping which occurs when the peak value of the audio output signal from the modulator exceeds the plate voltage of the RF amplifier. If the gain control is not set at minimum, mixing with the microphone is possible. A negative voltage then appears at the grid of V6, causing the two green indicating bars of the tube to overlap. In the latter service, the gain con- trol R4 is set to minimum and the second stage behaves as a grounded grid amplifier. That would be 40mW of audio. When the relay is energized at the transmit function of the transmitter , the relay contacts used for remote switching are closed and thereby the center-tap is grounded, causing the modulator plate supply to oper- ate.

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It had a great working clipper circuit, which the Ranger and DX60 did not.

Eico 730 modulator/ driver

When the relay is energized at the transmit function of the transmitterthe relay contacts used for remote switching are closed and thereby the center-tap is grounded, causing the modulator plate supply to oper- ate. Check the adjustment by speaking in- to the microphone quite loudly; loud speech should not be able to cause over. If you use it only to limit the excessive negative peaks, it is imperceptible, except to your neighboring frequencies who do modulatof have to listen to your splatter.

It used commonly available modluator hi-fi tubes used in the great Dynakit Stereo 70 amplifier. The operation eioc the remote control relay in conjunction with the modulator remote switching leads from pin 8 of the octal plug and ground is as follows: In addition the effec- tive speech level of the signal will be raised db.


Attache tag to the instrument, giving your home address and the trouble with the unit. You outgrew the DX60 once you upgraded. When the relay is not energized at the standby and tune functions of the transmitterthe center-tap is left floating and ejco modulator plate supply is inopera- tive.

The plate power supply of the modulator does not operate unless this center-tap is grounded. Yes, you can use a transformer to reduce the impedance for your speaker or headphones, but Mofulator also included a novel over modulation indicator which warned when hitting peaks below 0 percent, which would cause splatter. Do I need another matching transformer to get the load impedance down to 8 ohms? The original shipping carton is satisfactory, modulatir the original inserts ore used or sufficient packing material is inserted to keep the instru- ment immovable.

Eico modulator needs tubes. Transformers, capacitors, EM tube all good | eBay

Rectifier V7 filament not lit. The resistor loads the mod xfmr properly while still allowing you to hear the waveform. The ohm resistor will take the mod power and match modulqtor mod xfmr properly.

The result is a reduction of any spurious sidebands and a restriction of bandwidthof the modulated wave. You can improve both the Ranger and the with minimum changes, but the Ranger will never sound as good as the in my opinion.

Eico modulator/ driver

There is more cost with building a modular system like the The out- put of the clipper is fed throughalow pass filter LI, C5, and C6 to suppress high order harmonics generated by peak clipping. Connect the meter leads to the two TEST jacks on the rear chassis ap- ron.


modulato The transmitter ground binding post should be connected to a true earth ground. At the ON position, the center-tap is internal- ly grounded in the modulator and remote switching is dis- abled.

To afford conservative operation of the unit in areas of high line voltage, both IITV and V taps have been provided on the primary of the power trans- former.

Change C8 and C9 to 0. Sign in for more lists. There is no blocking cap on the mic input.

The use of feedback greatly reduces distortion and ex- tends the range of uniform frequency response, resulting in increased clarity and pleasantness of speech.

The key is to properly load the output with a resistor which will take the mod power.

You do not need to use any more than that for good conditions. Connect and solder the black-green lead to AC switch terminal Sl Note that pin 1 of the octal plug going to the connects to pin 6 of the octal plug going to theand that pin 4 of the plug connects to pin 4 of the plug.

This is very important. Set the instrument at the minus or nega- tive DC vojts functions and a range of not less than 50 volts or more than volts the closer the point on the scale at which the reading is to full scale, the more ac- curate it is.