CHEMANDY ELECTRONICS Suppliers of the unusual

Active Probe Type 2


Frequency 15 MHz to 3 GHz
Input Load ≈ 0.5 pF || 40 M Ohms
Maximum Input 14 Volts pp
Insertion Loss  20 dB ± 2.5 dB
Supply Voltage 6 Volts to 15 Volts
Output Impedance 50 Ohms
Probe Body Dimensions
16 mm x 120 mm


Price GBP £168.39

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This high frequency active probe has been designed for measuring voltage distribution on VHF antennas but could be used for fault finding on PCB's and other purposes. The whole construction of the antenna voltage probe is designed with the minimum of metal and small diameter cables thus causing the minimum disturbance to the antennas performance. The probe is operated without an earth connection from the antenna and relies on the grounding from the test equipment used. The input is designed to have the lowest possible capacitance and the highest possible resistance thus creating the minimum loading on the antenna. The probe has an attenuation of 20 dB ± 3.0 dB, making it a nominal x10 probe and it is expected that this loss will be allowed for in the test set up calibration process.  Attenuation is normally required in antenna measurements because the antenna is driven with something in the region of +5 dBm to +20 dBm and the measuring equipment (either a Vector Network Analyser or a Spectrum Analyser) normally requires an input of less than 0 dBm. The probe is designed to work up to 3 GHz as a general high frequency probe but it would not be possible to obtain accurate antenna measurement results at such high frequencies because of the probes capacitance loading the antenna.

The active probe on offer is one of a pre-production batch manufactured by Chemandy Electronics Ltd that has been produced to prove the manufacturing process and assess performance spreads. It may therefore have very minor manufacturing defects that are cosmetic and do not effect the performance.



[Probe 2 in presentation case] [Presentation Box from above] [Bottom part of presentation box] [Probe only] [Tip of probe]


Frequency Response

     The figure below shows an average insertion loss from a sample of 10 pre-production probes. The limits are shown as 20 dB ± 1.25 db from 15 MHz to 900 MHz and 20 dB ± 2.5 dB from 1200 MHz to 3.0 GHz.


[Graph of average insertion loss of probe 2]


The high frequency active probe comes with a twelve month warranty that covers everything except misuse, mechanical damage or static discharge. Although the probe is static sensitive, the input circuit does afford a certain amount of protection but static precautions must be taken. We reserve the right to judge if the item has been misused or suffered from static damage or wrongly applied supply voltage and if this is the case then may make the standard charge.  For repairs that are out of warranty or due to misuse or static discharge e.t.c. a standard repair cost of £50.00 + VAT will apply which includes the cost of postage within the UK. Postage abroad will be charged at cost and any taxes due after the probe is despatched will be the responsibility of the customer.



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