Building a Repeater

Two W1 Philips PRM8010Repeaters have always been a fascination of mine ever since I started playing with radios. The magic begins when you discover you ‘can get into one’ or a better description would be ‘to make radio contact with one’, as you never know who is listening and how far away they are.

An opportunity to do more with a repeater was made to me when the local UHF Amateur Radio repeater had a growing list of issues.

At the last Wimmera Amateur Radio Group meeting, we discussed it at length what could be done with it the repeater, but unfortunately the man who originally made the repeater was unable to physically look at it. So I put my hand up and offering to make one for the club with parts offered by some of the members of WARG.

Andrew Squires – VK3AS  has a new antenna to replace the current antenna.

img_2486Andrew Janetzki – VK3MIX offered an ID-O-Matic II by Ham Gadgets repeater controller to operate the new repeater.  Andrew had purchased it a while ago, but had been unable to get it to work. After inspecting it for a few hours, I confirmed Andrew’s suspicions and found that the PIC oscillator crystal was faulty.  The controller usually utilises a 20MHz TF-38 style crystal, which is not readily available at your local electronics shop. Fortunately I had a spare HC-49 style crystal in my junk box and I managed to make it fit.

PRM 8010 StickerThe Radios I am going to employ are two Philips PRM8010 radios that I picked up on eBay in 2011.  To be honest, I can’t remember why I purchased them in the first place, but it made sense to use them for this project.  They are W1 band radios, but hopefully I will be able to tune them down to Amateur 70cm Band easily, if not with a little persuasion.

 

Philips PRM8010 internalsCloser inspection of the radios caused some concerns when lifted the lid and discovered that they had been heavily modified.  Some of the SMD components had also been reorientated to fit the modifications.  At the time of writing I have managed to restore one of the two back to standard and it appears to be working.  Hopefully the second will be just as easy to restore.

Interface PlugPRM80 series radios have a data port mounted on the back of them to allow interfacing with other devices and also programming. Both the sockets are missing from the two radios I have, but I scavenged a socket from another radio and I will make one for the second.  I have also made up a two plugs to interface the radios to the controller.

Hopefully over the next couple of weeks I will managed to get the repeater operating on my workbench.  The case and power supply will be ordered soon and I am hoping to have it in service with in a month.

Stay tuned for further updates.