OTHER E M AND T EQUIPMENT

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Grid Dip Meter

EICO 710 Grid Dip Meter (1960's)

Grid Dip meters are used for checking the resonant frequency of  an oscillator for a transmitter or a radio receiver. It can be used to design circuits that oscillate or  in servicing to check if the oscillator is functioning. This is accomplished by attaching a coil supplied by the maker, then getting close to the coil of the circuit and watch the meter for a dip in the reading. That indicates a resonance has occurred.
EICO 443 Transistor and Diode Curve Tracer. Purpose of curve tracers are to match and evaluate the quality of a part. Connect this to an oscilloscope with and X-Y input and you can get the dynamic parameters of the part. The curves are a helpful aid to designing and finding the maximum power rating of a part.











Evaluating a 2N2219 transistor (signal test). The oscilloscope is a Tektronix 454.

Geiger Counter


Civil Defense Issued ODCM # CDV-700 Model 56. Made by Electro Neutronics Inc
 Issued in the early 1960's to monitor alpha and beta radiation levels in case of nuclear attack. Can also be used as a uranium ore prospecting tool.This model uses a Geiger-Muller tube as a pickup sensor. Readings can be read off the meter in count per minute or heard with headphones. Has a piece of uranium ore attached to the side to be used for calibration.

Specific Purpose Alignment Equipment

Monitor Crystaliner 201 (1950s  Mfg MONITOR Products, Los Angeles, CA)  
RF Alignment Source for Vintage Broadcast Receivers
This RF Generator consists of Crystal Oscillators set to various IF Frequencies used on vintage 
Radios for IF peak alignment and has the HI and LO Band Oscillator Alignment frequencies as well. Allows you to put an external crystal for a different frequency and has a built in 400 Hz modulator and variable RF attenuator. 
IF FREQUENCIES175, 262, 370, 455, 460, 465 and 470 KHz
RF Carriers600, 1000, 1400 and 1700 KHz
Crystals on Rotory Selector. The 4 Tubes are 6J5 triodes. One is used as a rectifier and the other three are crystal oscillators. The crystal on the chassis is the reference standard unit. These are FT-243 type crystals that date back to World War 2.

My Home Brew Vintage Radio Test Power Supply                                           

1988 Version




Both power supplies have been wired for electrical safety to minimize electrical shock hazard. 

ARC 1988 Article

2019 UPDATE BELOW: Beefed up A supply to handle up to 2.5 Amps for battery radios using 0.5 A UV201. Added new panel meters to read values more accurately. Gave front panel a facelift with clearer wording.
In 1988 I built a battery eliminator power supply with A, B  and C supplies to handle most battery operated vintage radios. The circuit was published in Antique Radio Classified on December 1988. It was the first time I had an article published. It used analog meters and multi-tap power transformer and incorporated solid state regulators including the Texas Instruments high voltage 3-terminal regulator the TL-783C which I believe is still the only one made. My early design had some errors, being a serious collector for about 5 years. I had the C battery referenced positive (should be negative), some switch position errors and component value changes needed to be made. This version went through several upgrades and I got more experience. Upgrades included changes in panel meters, addition of selectable B and C voltage monitoring, addition of a EMI and safety filter and fixing up the cabinet and making the power supply enclosed.                                             
ABOVE: 2019 Update. Relabeled panel with transfers, and replaced the 117Z6 dual rectifier with 117L7/M7GT. The new supply will encorporate a a vacuum tube rectifier with a silicon diode rectifier for current boost and the 117L7 beam tetrode section becomes a triode series pass or common cathode  circuit for better current handling.
2017 Version
Fast track to 2017 and I decided to make a more updated looking one but added some nostalgia into it. The new version, incorporates digital readouts, dedicated A supply to fit all versions of tube filament supplies, built in VARIAC to adjust AC supply for slow stress warmup, fixed B supply to fit all possible B supplies for battery radios and the addition of a vacuum tube rectifier (117Z6GT) instead of a solid state rectifier for nostalgia and delayed B+.                                          
Vacuum Tube Power Supply (JUNE 2019). Designed a power supply strictly for vacuum tube designs. With exception of rectifiers, this unit uses an 0B2 voltage regulator, 6AU6A Voltage amplifier and 2 6AQ5A cathode followers to provide 60-360 VDC 100 mA max  for B supply and 0- -106 VDC at 1mA  for C supply. Uses a Constant Voltage Transformer for stable input source for tube circuits.

                    Comparison of the two versions

          Circuit Layout 1988 Version                 Circuit Layout 2017 Version                           

All my home made power supplies for tinkering

Left to right:

+/- 1-20 V Supply up to 3A,  +/- 1-24 V Supply up to 1A,  60-360 V Supply up to 110 mA and Vintage Radio Supply & Short Ckt Adapter

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