Elecraft’s just announced a couple of new kits that builders and experimenters will find intriguing. Like their other products, they’re not cheap, but I’ll bet you get what you pay for.
I’m seriously considering buying the XG2. I would have loved to have one when aligning my KX1. That was the step that I had the most trouble with. I may even buy a couple of them, and sell them. Let’s see. If I bought five of them, and sold four of them for $75 a pop, I’d basically be getting mine for free. :)
The first new product is the XG2, a three-band, receiver test oscillator designed to help you measure receiver sensitivity. The Elecraft propaganda says:
The XG2 is a fixed-frequency signal source with switch selectable oscillator frequencies on 80, 40 and 20M. Its highly-accurate precision low-level crystal oscillator generates 1 microvolt and 50 microvolt output levels with an absolute output accuracy of better than ± 2 dB, and an extremely small unit-to-unit variation of typically ± 1 dB.
The 1-microvolt level can be used to determine a receiver’s MDS (minimum discernible signal), as well as its overall receive gain. 50 microvolts is widely used as the standard “S9” reference, so this level can be used for S-meter calibration. Step-by-step procedures are included for receiver performance measurement and S-meter alignment. In addition to receiver testing, the XG2 can be used as a reference to calibrate other lab instruments.
The XG2 also includes an on-board 3-Volt battery (standard coin cell) and a low current power-on LED. The XG2 typically draws 250 uA, resulting in an estimated battery life of 850 hours. The unit is protected against brief accidental transmit, and has been tested at up to 10 watts for 2 seconds.
The XG2 can be set to operate on 3.579.5, 7.040 and 14.060 MHz. It also provides reduced output levels at harmonics of these operating frequencies, so it can be used for receiver alignment and qualitative tests on or near most HF ham bands.
The XG2 is quite small: the PC board is just 1.5″W by 3.5″L. You can use a BNC male-to-male adapter such as Elecraft model BNC-MM to eliminate the coax cable and directly connect the XG2 to the back of a receiver or transceiver. Rubber feet are also included so the unit can be used on the workbench.
The XG2 is available now, and is priced at $59. The BNC-MM adapter is $5.
The second new product is the 2T-gen Two-Tone Test Generator, a module designed to help you make transmit intermodulation distortion (IMD) measurements. Elecraft says:
[The 2T-gen provides] a standard 2-tone (700 and 1900 Hz) audio source for testing of SSB transceivers and linear amplifiers. This type of testing is almost universally used as a measure of transmitter linearity for amateur radio equipment. (Linearity impacts both SSB fidelity and the amount of SSB splatter that causes adjacent channel interference.) Results of 2-tone IMD tests can be found in every ARRL review of new transceivers and power amplifiers.
The 2T-gen is battery operated and provides sufficient output level (0-200 mV) to be connected directly to the microphone connector of almost any transceiver. Transmitter linearity can then be observed either by observing the transmit signal 2-tone envelope on an oscilloscope or station monitor. For more exacting IMD measurements the output can be measured using a spectrum analyzer.
For the 2T-gen, F1 is 700 Hz and F2 is 1900 Hz, which results in a 3rd order product of 3100 Hz and a 5th order product of 4300 Hz. The amplitude of these undesired outputs is usually increased as the transmitter output is increased, and is caused by various transmitter amplifier stages beginning to operate in compression.
The PC board is just 2.5″W by 3.5″L. Rubber feet are also included so the unit can be used on the workbench. The 2T-gen is available now, and is priced at $59.
For further details on both products (including downloadable manuals), visit the Elecraft website.
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