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1200W HF Linear Amplifier from budget parts - 2

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While I'm waiting for the rest of the parts to turn up, I have started working out how to automate band-switching on the Low-Pass Filter module.  To do this, I am relying on the output of my IC-7300 transceiver to control this. If you want to skip ahead, the source code is located on my GitHub page:   https://github.com/au-chrismor/arduino7300 As noted in part 1 of this series , the IC-7300 outputs a voltage from 0 - 8V depending on the band selected.  The approximate values (from IC-7300 forums) are listed below: 630m     7.41V 160m     7.41V 80m        6.07V 60m        5.07V 40m        5.07V 30m        0.03V 20m        4.07V 17m        3.18V 15m        3.18V 12m        2.22V 10m        2.22V 6m          1.88V   My LPF has switch inputs for: 10/12m 17/15m 30/20m 40m 80m Fortunately a lot of these will line up, at least for my usual bands. However there seems to be a bit of dispute about the actual voltages.  Icom don't publish anything, which is not entirely surprising.   My

1200W HF Linear Amplifier from budget parts - 1

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This is either going to go very well or very badly, and if I'm honest it's 50/50 right now... I was scrolling through AliExpress (who doesn't?) and I came across a listing for a 1.2KW 1.8-54MHz LDMOS amplifier for a little over $A100.  Of course for this, it doesn't include the BLF188 device ($A300 from DigiKey).   Unlike most of the other amp packages on these markets, this one is assembled except for the LDMOS device, so there's no trying to interpret the schematic only to find it has nothing to do with the PCB you have on hand.   It didn't take long and the module arrived at my local post office.  It's small, at less than 100mm x 100mm and it appears to be quite well made: My research also tells me that a multi-band Low Pass Filter is an excellent idea and fortunately the same vendor has a nice unit at about twice the price of the amplifier module.  It arrived in the same package:   At about 250mm x 200mm it's substantially bigger than the amplifier,

The IDPROM contents are invalid

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  I like my old Sun machines , but they have a small weakness in their design.  The older machines use a real-time clock known as an "IDPROM".  This device, originally made by Dallas Semiconductor has RAM, Clock, Crystal and a Battery all in one package.  If you read that back, you will see the problem: "Battery" The battery has a lifetime in years, but when it goes, the machine loses everything stored in the IDPROM.  The problem is that this data includes the MAC address, Host ID, Serial Number and even system type.  Without this data, your machine won't boot; and if it does, you won't have network access in all likelihood. Now, the chip is in a socket, because Sun knew it would fail and need replacement in the field, and while some devices (M48T02 and M48T58) are still available, other common devices, especially the M48T59 are no longer available, and there aren't and pin-compatible alternatives that I can find.   There are instructions online showing

ImageBuilder and Terraform - Handy Hints

This is for my benefit as much as anybody else, because it took me a while to figure things out: Most of the time when you write for AWS ImageBuilder, the docs tell you to create separate YAML files containing your components.  That's fine, but what if you want to do dynamic substitutions on path and file names?  In that case you probably want to do the definition in the HCL language.  That is, within the actual Terraform code itself. Using S3 One of the more fiddly bits is pulling things from S3 to install on your new instance.  You need to do two things: Have an IAM policy which allows access; and Write the component to do the job Writing the IAM Create a policy resource that looks something like this: resource "aws_iam_policy" "s3_policy" {     name = "s3-policy"     policy = jsonencode(       {           Version = "2012-10-17"           Statement = [             {               Effect = "Allow"               Action = [