How to enable cross band repeater on an Icom ID-5100E

I own two Icom ID-5100E radios, I initially bought one for home so I could access the local D-STAR repeater GB7TE and I was so impressed with it that I bought another one for the car to replace my Kenwood TM-D710GE.

Whether it’s used for D-STAR or not, I’m still utterly convinced that the ID-5100E is the best VHF/UHF mobile wireless currently on the market. The receiver is good, it doesn’t get hammered by strong signals, the transmit audio is clear and most importantly, it’s simple and intuitive to use. The touch screen is visible in bright daylight and can be dimmed at night so it’s not dazzling to look at.

A friend and I were talking recently and he mentioned that the ID-5100E doesn’t offer a cross band repeater option. I was surprised by this and did some investigation because I was sure that I’d seen mention in various radio forums that this wireless can be switched into cross band repeater mode.

It appears that the model for the USA, the ID-5100A does come with cross band repeater enabled but the UK version, the ID-5100E doesn’t have this available.

I did some research and it seems that as is so often the case, the options can be enabled or disabled by the addition or removal of diodes on the main circuit board.

I decided to modify both my ID-5100Es to enable cross band repeater and while I was at it, I enabled the extended transmit range on both VHF and UHF as well. Each option requires the removal of a small surface mount diode so I had three on each radio to remove.

This is the time for me to say that you do this at your own risk. If you’re a bit clumsy with a soldering iron, get someone to do this for you. It will undoubtedly invalidate your warranty and if you mess it up, you could potentially destroy your radio.

I take no responsibility for any damage caused to your radio if you make this modification. In other words, if you do it and destroy your wireless, don’t come crying to me. You have been warned!

Before you start, save you radio configuration to the SD card via Menu / SD Card / Save Setting just in case you have to reload it afterwards. I didn’t need to do this but I’d have felt pretty silly if the radio had lost the entire configuration when I switched it back on.

The first thing to do is remove the bottom cover of the radio, this is the side without the speaker. There are four screws to remove, shown here in red circles. Be careful not to burr these screws over as mine were quite tight.

Icom ID-5100 bottom cover removal

With these four screws removed, there are four more, two on each side. Here’s a picture of one side, just remove these two screws and then rotate the radio and remove the same two on the other side.

Now prise the bottom cover off gently, it may need a little persuasion with a screwdriver and if so, be very careful not to damage the edge of the cover.

I’ve not been able to find good pictures of the inside of the Icom ID-5100 so here’s a very high resolution photograph. If you click any of the following two images, you’ll get the full size versions.

Here’s the inside of the radio showing the circuit board.

Icom ID-5100 circuit board

The area we’re interested in is the section highlighted in red. Let’s zoom in.

Icom ID-5100 showing which diodes to remove to extend transmit and enable the cross band repeater

The ID-5100A will already have the ‘Cross band repeater enable’ diode removed but other regions won’t. This picture is pretty self-explanatory, if you only want to enable cross band repeater, just remove one diode and if you want to expand the transmit frequency range, remove the appropriate diode.

I removed all three. I don’t have any special tools for working with surface mount components so I simply installed the smallest tip I have in my Weller PU-3D soldering iron, waited for it to get nicely hot and tinned the tip slightly. I heated one end of the diode and used a very small jewellers screwdriver to lift it off the board. Each one took about five seconds to completely remove.

They really are tiny!

Three diodes removed from my Icom ID-5100E

Now it’s time to test, I did this before I put the cover back on the radio.

Press Menu, scroll all the way down and select Others. Select Repeater Mode and then press on <<Repeater Mode>>
A box will pop up asking “Enter the Repeater Mode?
Tap the YES button.

Here you can see my radio is in cross band repeater mode, monitoring S14 on 2m and SU21 on 70cms. Any signal received on either band will automatically be transmitted on the other band. Please be aware of your local licence conditions before doing this.

Icom ID-5100E in cross band repeater mode

To exit cross band repeater mode, press RPT and select YES to the popup that says “Exit Repeater Mode?“.

With the test complete, reassemble the radio and you’re done.

This modification does not convert the ID-5100E to an ID-5100A, when the radio is switched on, the model type is still displayed as ID-5100E. By default, the ID-5100A already has cross band repeater mode enabled but will not have the transmit frequency range expanded. Removing the appropriate diodes on the ID-5100A as shown above should enable extended transmit.

Posted in Amateur radio, Construction, D-STAR, FM, How to ..., UHF, VHF | Tagged , | Leave a comment

Digital audio noise on receive when using WIRES-X

Back in February, I bought myself a Yaesu FTM-100DE with the intent to use it connected to a PC for WIRES-X. In the meantime, I’ve been using it to talk to friends via a YSFReflector and I wrote about how to build a Yaesu System Fusion reflector on this site here.

When I finally got around to using it with WIRES-X, connected to a PC in direct mode, I discovered a big problem with the received audio. Every single station I received had what I can only describe as a digital noise in the background. This wasn’t present during normal FM, wasn’t there when using C4FM to talk via a reflector and wasn’t there if I used C4FM simplex on either 2m or 70cms. It was present on both internal and external speakers and I tried numerous things to get rid of it, including wrapping every cable in and out of the radio around multiple ferrite cores. With hindsight, this was unlikely to resolve the problem because the radio wasn’t actually transmitting at the time, it wasn’t an RF issue.

You can hear what it sounds like by clicking the play button below or if that doesn’t work, click here.


To me this was unacceptable. Yaesu are very proud of the audio quality of WIRES-X and don’t like their rooms being bridged to other networks because it can potentially reduce the audio quality. In my previous post, I commented that I thought the quality of C4FM is better than D-STAR and DMR and so this digital noise was quite a shock to me.

My first point of call was to post in the WIRES-X group on Facebook where I had a lot of replies from people with the same issue but nobody could offer a definitive cure. I was advised to ask Yaesu in their official Facebook group. I joined that group and asked the same question as I hoped that out of the ten thousand members, someone might be able to offer some advice.
My post wasn’t even approved, instead I was advised to contact Yaesu support directly.

I emailed Yaesu in the UK who referred me to the retailer I’d bought the radio from originally so I contacted them and within a day they had an answer for me.

It appears that there’s a mod for the radio which eliminates this digital audio noise and it consists of just three surface mount components.

I asked whether I could do it myself but was told that it’s their job and I’d just have to return my wireless for them to fix it so I dutifully boxed the radio up and shipped it back.

A week later, my FTM-100DE has been returned to me and I’m very happy to report that the digital noise I experienced has completely gone. There’s no trace of it whatsoever, the audio is perfectly clear.

If you have this problem on any of your Yaesu radios, contact your retailer who should be able to easily and quickly fix it for you and be aware that if it’s under warranty, they shouldn’t charge for the repair. It seems that many radios suffer from this, it’s a common issue but it’s not normal and it’s not something you should live with.

Posted in Amateur radio, Data, FM, UHF, VHF, Yaesu System Fusion | Leave a comment

A new sign over the shack door

My wife bought me a sign to put over the shack door for Christmas, it’s the sort of sign where you get a blank board and have to fit the letters yourself. As I was quite immobile over the Christmas period, I didn’t get around to doing this until last week.

Telegraph Office shack sign

To avoid drilling through it to fix it on the wall, I used some strong double sided fixing pads.

It’s from Vintage Street Signs and I think it looks good up there.

Posted in Amateur radio | 2 Comments

UTC clock for macOS

As radio amateurs, time is important to us and Coordinated Universal Time (UTC), often called Greenwich Mean Time (GMT) is the most important.

We log our QSOs in UTC, (ideally) we give net times in UTC and our clocks need to be accurate to the second for data modes such as FT8, FT4, JT65, JT9 and WSPR.

For a long time, I had a piece of software running on my Mac which I had configured to show UTC in large text, overlaid on the bottom left corner of the screen. This was ideal as I could just glance at it and see the time including seconds.

Sadly the author of this software died some time ago and because it was a 32bit application, it stopped working when macOS Catalina was released so I spent some time looking for an alternative. I couldn’t find anything suitable and instead I looked for a clock I could configure in the menu bar to show me UTC time.

There are many clocks available but none which suited my needs. They all offered far too many functions such as multiple time zones, alarms, moon phase but none of them would give me just UTC including seconds.

I contacted the author of one of these and he very kindly offered to write something for me which does exactly what I wanted.

The result is a Mac application called “Menu Bar UTC” which does nothing more than sit in your menu bar and display the time in UTC, including seconds. It’s customisable so you can set it up exactly how you want and because that’s all it does, it consumes practically zero system resources.

Menu Bar UTC - macOS application

If you have a Mac, I can recommend this handy little utility and thanks to Steve Foster for writing it.

Posted in Amateur radio, Data, FT8, JT65, JT9, WSPR | Tagged , | 1 Comment

Social Distancing

Amateur radio enthusiast guide to social distancing

You can get this design on a t-shirt from Redbubble by clicking here with proceeds going to Age UK.

Be safe.
73 Keith G6NHU

Posted in Amateur radio | 2 Comments

Shack maps

Maps are important to radio amateurs – We like to make contact with countries all around the world so a good map is essential.

Some years ago I bought an Amateur Radio World Prefix map from DXMaps and it’s been on my wall ever since. I noticed that there was a tiny minor printing error on the map and contacted Mike, GM0PHW at DXMaps who very kindly sent me a replacement free of charge. Thanks Mike!

I really recommend these maps, they’re large, easy to read and printed on good quality glossy paper. That makes them quite difficult to photograph and this picture really doesn’t do it justice.

Amateur Radio World Prefix Map by DXMaps

Although this is an excellent map, the one I probably look at the most is the Great Circle map I have stuck to the inside of the shack door. When you look at a flattened map, like the one above, you assume that if you want to work North America from the UK, you’d point your aerial due west. Due to the shape of the earth and how this sort of map projection works, that’s not quite true. A Great Circle map shows the actual direction to point your aerial.

As you can see from the map below, if I want to work North America, the correct direction to point my beam is from 290° to 340° not 270°. Realistically, HF beams are quite wide so that it won’t make a lot of difference to stations on the east coast but consider that New Zealand is anywhere between 10° and 70° rather than the 140° you’d think from the map above and you can see how important a Great Circle map is.

This Great Circle map was produced from NS6T’s web page here. I simply put my latitude and longitude in the Location box (although it will take a grid locator), set the maximum distance to 19500, changed the paper size to the largest available and hit ‘Create Map’. This gave me a pdf file which I took to a local printer who charged me about £3 to print it. The paper isn’t great but it really doesn’t need to be as it’s just a very quick visual aid. I did intend to find somewhere who could do it on better quality paper but this is perfectly adequate for what I want.

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A quick tip for your hotspots

With all the hotspots I have in the house for various modes, I decided to do something about the RF. They all run very low power but they’re only for me to use and I didn’t want the RF escaping the house.

I bought a few tiny little dummy loads from eBay and replaced the rubber duck aerials on my hotspots with them. I’ve checked and I can still access them from anywhere in the house and that’s all I need. I picked that supplier because he’s in the UK and delivery is very quick, there are other sellers who will supply packs of five for the cost of two from him but they’ll arrive on the slow boat from China.

These dummy loads have the benefit of being nice and small and having perfectly flat SWR across both 2m and 70cms which is far better than the supplied rubber duck aerials. Of course, if you want to use your hotspots at any distance further away then this isn’t a tip I’d recommend.

Hotspot with dummy load instead of the supplied rubber duck
Posted in Amateur radio, D-STAR, DMR, Hotspot, How to ..., Raspberry Pi, Yaesu System Fusion | Tagged , | Leave a comment