The LP-500 (Optional Coupler Required) is a Digital Station Monitor which displays detailed information about the transmitted signal of a station. It displays the sampled signals in numerous formats including Power/SWR, various oscilloscope type displays and a spectrum display.
The sampled signals are obtained by demodulating the RF, like in a traditional wattmeter, and should therefore work on any frequency for which there is a suitable directional coupler with the appropriate voltage scaling and time constants. It should be noted that demodulated samples are audio frequency based and not the same as RF samples. With some types of modulation, the demodulated audio is not a linear representation of the modulation signals, therefore the spectrum display works quite differently than a true spectrum analyzer. This doesn't pose a problem for AM signals, where the demodulated audio is faithful to the modulation signal, but is a challenge for SSB and other signals without a carrier. For this reason, we have developed special test signals which allow for some traditional SSB tests to be performed, although the tests cannot be directly compared to measurements from a true spectrum analyzer. In many cases, though, similar information can be gleaned from the tests, and they can be used for comparative tests to see the effect of changes to the transmitting equipment.
Specifications:
(Specification Below Were Taken With Optional LPC-501 coupler) Subject to change without notice
General:
- Power Range… 0.1W to 3KW PEP (1500W Average)
- Absolute Power Accuracy… +/- 5% at 7 MHz, 10 to 1500W
- Flatness… Better than +/- 3% from 1.8 to 54 MHz
- (+/- 1% typical from 1.8 to 30 MHz)
- Directivity... >30 dB, 1.8 to 54 MHz
- Return Loss... >30 dB, 1.8 to 54 MHz
- SWR Range… 1.00 to 9.99
- SWR Accuracy… ~5%
- Bar Graph Resolution... 600 steps for each range, Manual or Auto-Ranging
- Number of Channels… 8 simultaneous (FWD & REF power for 4 couplers)
- Channel Balance... +/- 0.1%
- Memories... Range & Alarm settings are saved per channel
- Channel settings are saved per mode
- A/D Converter 16-bit / 200ksps, plus oversampling (2X to 16X).
- DAC Resolution… 18-bit, 96 dB SNR
- Screen Refresh… 5 Hz to 70 Hz, depending on mode, sweep/span settings.
- Sampling Rate… 2.5k to 80 ksps, depending on mode, sweep/span settings.
- Display Resolution 800 x 480 pixels (WVGA)
- Display Type TFT with White LED Backlight
- Display Size LP-500 - 5" Diagonal
- Test Tone Output… 250 ohms, 350-500mVpp, unbalanced, 0.01% THD into 10K load
- Power Requirements… 12-16VDC @ 800 mA maximum
- Size: LP-500 - 9.125"W x 6.1"D x 4.88"H (23.2cm x 15.5cm x 12.4cm)
Scope:
- Sweep Rate … 1.0 to 20.0 ms/division in 0.1 ms steps
- 5 Factory Presets and 3 User Adjustable Presets
- Display Modes … 7, including 4 split screens
- Trigger Modes … Normal, Plus, Minus, Plus/Minus, Free Running.
- AM Modulation % … 0 to 150, positive. 0 to 100 negative.
- Cursors … 2, measuring peak voltage and time (ms)
- Markers... 1 or 2, adjustable to show preset power limits
Spectrum:
- Frequency Spans... 2.5, 5.0 & 10.0 kHz, w/linear or log scaling
- Span Multiplier... 5X (500 & 1000 Hz, linear)
- RBW… 1 to 20 Hz, depending on span
- Averaging… 2X to 16X
- Full Scale Reference… +45, +55, +65 dBm
- ADC Dynamic Range… > 90 dB
- Coupler Dynamic Range... Up to 80 dB, depending on modulation type
- Cursors … 2, measuring peak power (dBm) and frequency (Hz)
- Markers... 1, adjustable to show preset power limit
