CHEMANDY ELECTRONICS Suppliers of the unusual

VHF Broadband Amplifier in Mini FLEXI-BOX


High Frequency Amplifier 300 KHz to 300 MHz
Gain 16.2 dB ± 0.2 dB @ 50 MHz
Gain Ripple < ± 0.2 dB
Output Power > 5 dBm @ 1 dB compression
IP3 @ 100 MHz +23 dBm
Input & Output Return Loss > 20 dB
Impedance 50 Ohms
Supply 10 to 17 Volts @ 74 mA
Box Dimensions 50 mm x 35 mm x 23.5 mm


From GBP £26.93 + Connectors
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The price of the VHF Amplifier in a Mini FLEXI-BOX is dependant on the connectors required. To find the price for your connector preference or to make a purchase, select your connector requirements in the boxes beside the photograph below and then hit "Add to Cart". 



  [Photograph of VHF Amplifier Box showing connectors]



The Very High Frequency amplifier is built in a Mini size FLEXI-BOX on a dedicated PCB. The screened box has one 50Ω input and one 50Ω output. It can be used as a test measurement aid or a general purpose VHF amplifier. The DC input is fitted with a feed through capacitor with a solder tag and can be supplied with 11 to 17 Volts thus making it suitable for radio hams running a +13.8 Volt supply system. The RF connectors can be selected from BNC, N, SMA and TNC. Other connector types could be fitted if required in quantity. We can build and test these at Chemandy with a gain of 16.2 dB ± 0.2 dB and a 1 dB compression output power from greater than +11 dBm at 50 MHz to greater than +5 dBm at 300 MHz, the gain ripple is less than ± 0.2 dB from 0.3 MHz to 300 MHz. Input and Output return loss are both better than 20dB across the whole frequency range. The amplifier does perform well down to about 50 KHz but is not tested in production to less than 300 KHz.

 The amplifier is referred to as being an VHF amplifier but it can be seen in Figures 1 and 2 that the frequency response is far wider than just the VHF band and it could also be used for LF, MF, HF or VHF.


[Graph of VHF amplifier gain]

[Graph of VHF amplifier input and output return loss]

     The isolation S12, has been omitted because it is better than -65 dB from 0.3 MHz to 300 MHz and would cramp the scale of the other measurements.

     The above results were obtained with SMA connectors and the performance will most probably be inferior with any other type fitted.

A selection of escutcheon drawings are available for downloading as .zip or .bmp files.