Difference between revisions of "Receiver Performance Tests"
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[[Image:45 Ohm combiner.jpg|thumb|300px|Formulas and Values for a 45 Ohm Hybrid Combiner]] | [[Image:45 Ohm combiner.jpg|thumb|300px|Formulas and Values for a 45 Ohm Hybrid Combiner]] | ||
| + | [[Image:Homebrewcombiner.jpg|thumb|300px|Homebrew 45 Ohm Hybrid Combiner]] | ||
The Hybird combiner was made from an old PC network splitter. The device was found in an used PC warehouse. It was a four port device with 4 BNC jacks on it. On inspection of the device, we found that it was a resistive splitter with four 39 Ohm resistors connected to each BNC center contact and a common point. These were removed and replaced with 15 Ohm 2 Watt 2% resistors metal film resistors (NTE 2W015 Flameproof Resistors). | The Hybird combiner was made from an old PC network splitter. The device was found in an used PC warehouse. It was a four port device with 4 BNC jacks on it. On inspection of the device, we found that it was a resistive splitter with four 39 Ohm resistors connected to each BNC center contact and a common point. These were removed and replaced with 15 Ohm 2 Watt 2% resistors metal film resistors (NTE 2W015 Flameproof Resistors). | ||
[[Image:Stepattenuator.jpg|thumb|300px|40 dB Step Attenuator purchased at the 2009 Indy Radio Club Ham Auction for 25 Cents]] | [[Image:Stepattenuator.jpg|thumb|300px|40 dB Step Attenuator purchased at the 2009 Indy Radio Club Ham Auction for 25 Cents]] | ||
Revision as of 08:07, 23 October 2009
Contents
Instruments required
- Two (2) Signal generators
- Hybird combiner
- Audio AC voltmeter
- Distortion meter (FM Only)
- Noise figure meter (for noise figure measurements only)
- Two (2) step attenuators with 10dB and 1dB steps
The signal generators at the W9KFB lab are as follows:
- HP 3586B Selective Level Meter (dBm measurements are calibrated for 75 Ohm characteristic impedance, signal is 0 dBm out only at the level measurement frequency)
- HP 8656B Signal Generator 0.1-990 MHz (dBm measurements are calibrated for 50 Ohm characteristic impedance)
The Hybird combiner was made from an old PC network splitter. The device was found in an used PC warehouse. It was a four port device with 4 BNC jacks on it. On inspection of the device, we found that it was a resistive splitter with four 39 Ohm resistors connected to each BNC center contact and a common point. These were removed and replaced with 15 Ohm 2 Watt 2% resistors metal film resistors (NTE 2W015 Flameproof Resistors).
