The personal website of Scott W Harden

Upgraded Amplifier

The design is similar (CMOS buffer driving an IRF510) but I used perfboard to make this one and placed it in an enclosure. There's no low-pass filter on the amplifier itself, but I put a 30m low-pass filter in-line the coax before the antenna. It's currently outputting 20PPV into 50 ohms (1 watt).

Old Amplifier

New Amplifier

Right after hooking it up I saw my signal looking nice on the air:

AJ4VD Spotted in Ontario, Canada (VA3ROM)

AJ4VD Spotted in the Canary Islands (EA8BVP1)

Markdown source code last modified on January 18th, 2021
---
title: Upgraded Amplifier
date: 2019-07-31 21:00:00
tags: qrss, circuit
---

# Upgraded Amplifier

The design is similar (CMOS buffer driving an IRF510) but I used perfboard to make this one and placed it in an enclosure. There's no low-pass filter on the amplifier itself, but I put a 30m low-pass filter in-line the coax before the antenna. It's currently outputting 20PPV into 50 ohms (1 watt).

### Old Amplifier

<div class="text-center img-border">

[![](2019-07-30-old-amp_thumb.jpg)](2019-07-30-old-amp.jpg)

</div>

### New Amplifier

<div class="text-center">

[![](schematic_thumb.jpg)](schematic.png)

</div>

<div class="text-center img-border">

[![](2019-07-31-new-amp_thumb.jpg)](2019-07-31-new-amp.jpg)

</div>

Right after hooking it up I saw my signal looking nice on the air:

### AJ4VD Spotted in Ontario, Canada (VA3ROM)

<div class="text-center img-border">

[![](VA3ROM.1907311950.549006f9e5_thumb.jpg)](VA3ROM.1907311950.549006f9e5.jpg)

</div>

### AJ4VD Spotted in the Canary Islands (EA8BVP1)

<div class="text-center img-border">

[![](EA8BVP1.1907311940.821b800321_thumb.jpg)](EA8BVP1.1907311940.821b800321.jpg)

</div>