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    Weston Technology Remote Display Unit

    I found this Remote Display Unit, it also has a LC/SDCM Serial Data Converter Module (for use with DayStar NOVA LCD). I have the following information: There are (4) terminal connections: Power Supply Return, 5V Power Suppply, RS-232 Return, Receive DATA. It is a receive -...
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    Thermocouple RF Ammeter

    I'm toying with the idea of making my own replacement thermocouple for my High frequency Milliammeter.. We use to make our own K types in the lab by twisting the thermocouple wire together and gas welding the junction. The theromocouple in the meter appears to be one type...
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    Thermocouple RF Ammeter

    Having trouble uploading files. I Tried to send a scan of page 512 of 1978 ARRL Handbook. The same text and photo appears in other handbooks. It clearly shows the same RF Ammeter (Same one I have) mounted in a Bud Box with a SO-239 Connector in and SO-239...
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    Thermocouple RF Ammeter

    I agree any device inserted along a transmission causes a bump in impedance. (Any). I too, have a Bird 43. It is a directional coupler and completely different in operation compared to an ammeter. An ammeter was typicaly used in the plate loading circuits of military...
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    Thermocouple RF Ammeter

    I like your vacuum tube contained true RMS device. From the photo it appears to be (3) wire device. Current in and current out, and sensor. I'm curious. Does the sensor connection between the In and Out constitute two junctions or one.. Since only one wire is...
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    Thermocouple RF Ammeter

    Interesting discussion, thank you both. Actually, I'm thinking you cannot get much more accurate and simpler than measuring heat produced to determinie RMS value. Frequency should have no bearing, aside to physical limitations. In my youth I determined resonance of my...
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    Thermocouple RF Ammeter

    Example 1 is a GE 8DW52AA! Thermocouple Type RF Ammeter I found a good description on u-tub It has a built in thermocouple, and measures true RMS via heat produced.(independent of frequency). I believe this wo ld make it useful for measuring antennae current, for calculating...
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    Thermocouple RF Ammeter

    What is the characteristics of the thermocouple device used with a thermocouple RF ammeter? I have several meter movements labeled in RF Watts, but missing the probes. Are these typically J or K type thermocouples, or thermopiles? Or, are they shunts with a thermocouple...
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    Choose Software or Hardware in electronics ??

    Depending on what industry you choose to work will dictate the skills needed to succeed. I have worked in several industries. In manufacturing image tubes, and display device it was hardware. Working in the Natural Gas Transportation industry ( Process control) software...
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    Don't Bin that Microwave!

    Paint chipping doesn't surprise me, especially with white enamel. I try to pick up only the black or wood grain finish when I find them. I use the covers as they are without bending. I let the front slightly protrude beyond the front panel, sort of a shadow box design. I...
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    Don't Bin that Microwave!

    I salvage the cabinet covers. I bend 1/8 aluminum into a u-shape for my project and use the salvaged cover to finish.. Small microwave ovens are just right for some of my larger projects.
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    Inductor/power supply choke operation

    So, technically, as the current fluctuates through an air-gapped power supply filter choke the Inductance changes, and therefore its reactance. The inductance changes because the physical conditions are changed. Varying the flux is the same as increasing or decreasing the...
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    Inductor/power supply choke operation

    I was mis-using the terms inductance and Inductive reactance.(Big difference, thanks I stand corrected). I thought I had read in a text, that chokes inductance is greater when no current is being drawn, and decreases as it reaches saturation. I best revisit; probably was Inductive...
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    Inductor/power supply choke operation

    I'm familiar with the formula for Inductive Reactance, and realize Inductance, is directly proportional to frequency change . I also know as the DC current increases the Flux increases until saturation . At saturation (critical) Inductance is .at a minimum because the Flux no...
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    tuned (tank) circuit, oscillator, Q

    A specific C and L theoretically resonates at a specific frequency. In the real world there is always some resistance within the components. This resistance broadens the response, thus the tuned circuit resonates a little higher and lower. Resistance in a tuned circuit...
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    Transistors

    Check and see if there is a bias potentiometer near these transistors. The bias adjustment sets the bias such that the output stage run s in the linear part of the output curve. If this gets out of adjustment the transistors can run hot and destroy themselves. I recently...
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    Filter Choke for power supply

    Upd ate:
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    Filter Choke for power supply

    Looking at the schematic and circuit description of the LM-13, it appears it actually runs with 135 V. The 180V of battery (4 X 45V), is then regulated by a series resistor and two Neon regulator bulbs. It has the option of 260- 475 volt operation with repositioning of a...
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    Filter Choke for power supply

    If your interested, this is how I mounted the wall-wart in my chassis:
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    Filter Choke for power supply

    My Bad again!, I meant (4) 45 V batteries. Thanks Duke! I have B C-221 as well, but that's a different project. The LM-13 (current project) uses (4) 45 V batteries. I was planning on using a 12V, 1000 mA wall-wart for the filaments, It measures 14 VDC when connected...
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