Tag Archives: HAM Amateur Transceivers

PALOMAR HIGH POWER REPLACEMENT FINAL AMPLIFIER

Under the name POWERBAND, the company PALOMAR in USA sells a line of
4 types of high power replacement final amplifier sections with high performance low pass filter for 10 meter amateur transceivers.

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After RFX75 and RFX150 they now introduce the RFX85 and RFX85HD.

RFX75

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RFX75 is an Amplifier, 75 – 100 Watt PEP Output Power, RF Final Output Stage and Low Pass Filter, Designed as a replacement and/or upgrade for most 10 meter amateur transceivers.

The RFX75 is a RF final output stage and low pass filter designed as a replacement and/or upgrade for most 10-meter amateur transceivers.
The RFX75 features the latest Power MOSFET technology and a built in S-meter detection circuit.
The output power of the RFX75 varies depending on the transceiver that it is installed on. Most installations will see 75 – 100 watts PEP output power.

THEORY OF OPERATION OF POWERBAND TYPES, DESCRIPTION OF RFX75:

a) The RFX75 replaces the transceiver’s final amplifier stage and low pass filter section.
The RFX75 is NOT a standalone amplifier. The RFX75 mounts to the back of most transceivers with little or no modification to the transceiver’s chassis.

b) Once installed, the transmitted RF signal from the output of the transceiver’s driver stage (or pre-driver stage) is sent to the RFX75 via the coaxial cable marked RF IN.

c) The driver signal is then amplified through the RFX75‘s ERF2030 (FET1) and then again through the ERF7530 (FET2).

d) The amplified signal from the ERF7530 passes through the RFX75’s efficient low pass filter.

e) A small portion of the signal is sampled through C19 and rectified through D3 and D4. This is sent to the S-meter detection circuit in the transceiver through the yellow wire.

f) The final RF output signal of the RFX75 is sent back to the radio through the RF OUT coaxial cable where it is connected with the transceiver’s antenna connector*.

g) The incoming receive signal is sampled from C14 and connected to the receive strip of the transceiver through the RFX75’s coaxial cable marked RX OUT.

* It is possible to attach the RF OUT coax directly to the antenna connector. However, it is recommended to attach it to the transceiver’s PCB because some transceivers come equipped with antenna warning systems, or other circuits, that are on ancillary boards between the recommended connection point and the antenna connector.

RFX150

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RFX85 and RFX85HD

There are now 2 RFX85 Choices: the Standard RFX85 and the New RFX85HD High Drive.

The RFX85 Circuit includes driver stage, final amplifer stage and low pass filter. The RFX85 is your choice for 10 meter radio repairs and upgrades that require replacing the radio’s driver and final amplification stages.

The RFX85HD circuit includes only the final amplifier stage and low pass filter which makes for a much quicker and easier installation.

The RFX85HD is your choice for 10 meter radio repairs and upgrades when all your replacing is the final transistor or no transistors.

Both RFX85 units feature the new fan-ready heatsink design and variable bias controls for better tuning on SSB radio installations.

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RFX85

RFX85 SPECIFICATIONS:
– Maximum Output: 100 Watts PEP.
– Drive Stage: ERF2030 MOSFET (x1).
– Final Stage: ERF7530 MOSFET (x1).
– Low Pass Filter: 3 Stage.
– Spurious Emission Suppression: 45 dB.
– Supply Voltage: 13.8 VDC.
– Power Consumption: 12 Amps Max.
– Dimensions: 5.1 x 8.3 x 4.2 cm (LxWxH).
– Weight: 235 gram.

5RFX85HD

RFX85HD SPECIFICATIONS:
– Maximum Input: 30 Watts PEP.
– Maximum Ouput: 100 Watts PEP.
– Final Stage: ERF7530 MOSFET (x1).
– Low Pass Filter: 3 Stage.
– Spurious Emission Suppression: 45 dB.
– Supply Voltage: 13.8 VDC.
– Power Consumption: 12 Amps Max.
– Dimensions: 5.1 x 8.3 x 4.2 cm (LxWxH).
– Weight: 235 gram.

It is necessarily to have good technical knowledge to install RFX types.
In USA these amplifiers are very popular and on the internet you can find many videos and reviews.
That might help to be prepared when installing the first RFX.

Here are some links, but many more can be found:

For many radios the installation instructions have been published on the following website:
www.cbtricks.com:80/miscellaneous/accessories/power_band/rfx_75/index.htm

LINK(S) TO VIDEO OF THIS PRODUCT:
www.youtube.com/watch?v=esDX2lVRTb0feature=related

All 4 models are available at Avera Distributing