QRP-LABS QMX+ SPEAKER MOD

WITH BOB NAGY'S HELP!

I recently saw a post on Facebook where Bob Nagy (AB5N) had fitted an internal speaker to his QMX+ and I was keen to do the same, so I ordered the same Audio Amplifier and what I believed would be a suitable speaker.

When the components arrived, I realised that it wasn't immediately obvious where to make the connections between the audio amplifier and the QMX+ PCB, so I contacted Bob and asked him for help with the connections.

Very kindly, Bob obliged and told me where the connections go. Honestly, this is the sort of help that few people can be bothered providing and I gotta say that I am extremely grateful for his assistance and guidance 👍👍👍.

So the first job of course was to dismantle the QMX+ and decide where to place the speaker. There's plenty of room in the cabinet, but I was still keen to position it in a location which gave it the most clearance. One thing that crossed my mind was "Might there be an additional upgrade pcb from QRP-Labs in the future that might force the removal or relocation of the speaker"? Who knows? 

Anyway, I picked a spot and marked four 5mm mounting holes for the speaker. Then I drilled another series of holes for the sound to pass through. To prevent bits of dust and crap falling through the holes and sitting on the speaker cone, I fitted a fine black gauze over the speaker (my apologies to the wife - she's convinced she had a new pair of black tights somewhere) 😂.

It's worth noting that I used a pillar-drill when drilling the holes - using a hand drill will almost certainly lead a messy set of misaligned holes. And make sure you use a new, good quality metal drill bit. 

You need a short length of thin shielded cable to connect to the headphone sub-pcb.  I say thin because there’s already almost no clearance between the pcb and the bottom of the enclosure, so adding a cable makes it even tighter!

You also need some regular cable to connect to the speaker and to a suitable power feed. 

Bob had chosen to pick up the power for the audio-amp from the QMX’s power-connector and I did the same, but I’m sure there’s other options available if you know how to read the circuit diagram. To make it simple for others wanting to try this simple mod, I've done a sketch showing the layout of the wiring...

Figure 1

With the QMX+ dismantled, attach the shielded cable to the underside of the mini-pcb and feed the cable through one of the holes of the main pcb as shown below.

Connect the other end of the shielded cable to the IN and GND of the amplifier board as shown in Figure 1, putting the shielding to GND and the center-core to IN.

When you've completed the soldering, use a double-sided sticky pad to attach the audio amplifier to the back of the radio's rear panel (middle top) and start to reassemble the radio.

All that's left to do is pick a spot for the loudspeaker and drill the holes. Unfortunately, I had no black bolts for my speaker mounts, so I had to fit silver for now. I've ordered some replacements to make it look nicer.

That's it! All working well. I should point out that Bob said to change the Volume Increments to 2db because the QMX+ will over-drive the little amp. During final setup and testing, you might want to look at adjusting the trimpot on the amp for best volume levels. Just experiment 👍

Just a note on the feed from the underside of the PCB - I think (now) that it might be possible to pick up a feed from ABOVE the board to save squeezing that shielded cable underneath. See the diagram below and make your own mind up...

Anyway, it's all done for now and I'm happy with the mod and the way it sounds. Thanks again to Bob Nagy for his help 👍.

73, Tom, M7MCQ.

 

MFJ-401D ECONO KEYER II

I've been using an MFJ-401D Econo Keyer II  to practise knocking out some clumsy code 😁 and I've always connected it to a power supply - never even bothering to try putting a battery in. Then tonight I decided to open it up to insert a PP3 battery and lo and behold it already had one fitted!!

I unplugged the power supply and switched the keyer on - to my amazement it came on and worked. I thought it was best to swap out the battery anyway, because I didn't know how long it had been in there, and then I spotted that the battery's expiry date was 10 YEARS GO!!

So that little Panasonic had probably been in there from new! Wow, I have a lot more respect for Panasonic batteries now 💖😂

 

As an aside, this keyer is a great little device. I got it free with a used radio and it's a delight to use. Built-in speaker, volume control and speed control, all easily accessed from the front.

73, Tom, M7MCQ.

DX-FT8 TABLET TRANSCEIVER

PORTABLE FT8 ANYONE?

While browsing AE5X's excellent blog, I saw a post about a forthcoming product which is due to be made available some time in early 2025.

It's a portable QRPp 5-Band FT8 Transceiver Tablet with a touch-screen. It covers the 10, 12, 15, 17 & 20M bands and puts out less than 1W with a 5V power supply (perfect for using with a small USB Power Bank). It's going to be less than 7"x4" in size which pretty much makes it a pocket-radio! I just love this ultra low-power stuff - it's what keeps me interested in the hobby.

Following further enquiries, I immediately placed a pre-order for one from K5BCQ and it will hopefully be shipped out in February. These kits cost around $40, so no big investment required.

In the meantime, I have also ordered (and received) another item which you have to obtain separate to the kit - the STM32 Development Board from Digikey.

 

I'm very much looking forward to building this kit and will review the completed product in due course. You can find out more about this project by visiting THIS WEBSITE.

I’ve created a FACEBOOK GROUP for anyone who wants to share info/tips/help on that platform. I’d be delighted to see you join, if it’s of interest to you 👍

73, Tom, M7MCQ.

LOWE SRX-100 / TARGET HF3

SWEET SOUNDING RADIO

We've all got our favourites from the 1990's haven't we? For me, there were a few receivers that I remember very fondly and they include the AOR AR-3000A, the LOWE HF-150 and later the LOWE SRX-100 (or as many know it here in the UK - the TARGET HF3).

The HF3 was a bit of a downgrade to my beloved HF-150, but at the time, I was feeling a bit skint and this new budget receiver was getting some great reviews, despite it being a third of the price of others, so I bought one and loved the sweet sound.

As much as I had enjoyed my ownership of the 150 a few years earlier, I had no problem admitting that the HF3 was much nicer to play with. Tuning around (1kHz steps) was very easy and it had that progressive tuning which meant that the quicker you spun the dial, the quicker the tuning rate increased. By comparison the HF-150 was a royal pain to use in SSB mode - OMG it was soooo slow!

A Clarifier dial on the HF3 allows you to fine tune in between the 1kHz steps and generally worked well. Back then (I feel), ham operators tended to stick to round numbers when calling QC - eg 14.240.0 but these days there seems to be a hell of a lot who make a point of going in between eg 14.240.5 which makes tuning around more awkward on this radio. 

I should mention that the calibration of this radio is out by a couple of kHz, but that's pretty standard - my AR3000A is almost 4k out - doesn't really matter does it?

The receiver is very well built, presented in a fairly compact case with a great sounding speaker on top. The rear panel has a port for an external speaker AND the Data output for WeFax, because it is the later "S" model. The radio has a lovely warm sound which makes you comfortable with extended listening times - easy on the ear - something we all like.

One thing which I definitely remember is how sensitive it was to the antenna being used. Chucking out a length of random wire was never the way to go. The HF3 benefits from a decent antenna being attached.

These days I use this radio to listen to the ham bands and to be honest, I don't sit there trying to pull in weak DX stations - I just tune into the stronger signals and enjoy the QSO's. On SSB the radio uses a pretty wide 3.8kHz filter. On AM it uses 6kHz (there's no swapping between them). Apart from the ham bands, I also like to take a spin on MW & LW and I find the HF3 to be particularly good here.

The screen is a simple LCD and that's the beauty of it! No fuss, no graphics, no need for reading glasses, lol. Just spin that dial and enjoy what you pick up. The coverage, by the way, is from 30kHz through to 30MHz with no gaps.

It's a great receiver which is incredibly easy to use! I find it good fun to use and pleasant to listen to in a comfortable chair with a hot drink 😀. 

But to be honest, I think it's about time to let this go - my shack is getting smaller and smaller, so I've packed it all up and I'm probably going to put it on HamRadioDeals or eBay. It'll be a great find for someone and give them many years of reliable service. (Update - Sold).

The radio is still available for sale new - mainly in boating outlets were people favour it for its ability to provide weather reports with relevant software...

www.4boats.co.uk

Fitted with external speaker port

HAM RADIO = GOOD HEALTH!

I think I've touched on this subject before. Hobbies are good for your health! I have no doubt about it.

 

Over the last few weeks (months even), my health has not been in a good place and most of is relates to stress. I won't harp on about what's causing the stress, but the end result has been extremely poor sleep, constant worry and very high blood pressure (typically 195 over 104)😲  My doctor has started to treat my BP with an increase in medication, but it's not dramatically different up to now. 

This weekend I spent all day in the shack - it had become untidy and looked a right mess! That in itself brings me down a bit, so I decided to devote the day to sorting everything out and then I spent the rest of the weekend in there playing radio.

It was just what I needed! I was relaxed and enjoyed myself immensely, not giving a thought to my worries. A BP measurement late on this afternoon gave me a reading of 154/84 which is about the best I've had in quite a while.

Don't neglect yourself! Take time out to do something you love - something which demands your attention and therefore keeps you focused on the good stuff in life.

73 my friends!

Tom, M7MCQ.

DO I NEED A TOP-END RADIO?

SO MUCH - FOR SO LITTLE

Goodness knows, I've had some amazing radios in my shack over these last few years and they varied wildly in cost, from £40 to £4,000. They've ranged from tiny, plastic kits to huge, metal boat anchors! From button-less to button-overload. From old Superhets to modern SDRs. I've enjoyed them all.

I've usually bought wisely but sometimes bought foolishly, overall though, I've done pretty well out of it - managing to find some outstanding bargains and selling them on for profit after playing around with them for a few months. I've been doing the same thing with motorbikes most of my life. It's my 'thang' 😂

But I find myself returning to the same three radios over and over... the bargain Hermes HL2 PLUS, the highly regarded Elecraft KX3 and the magnificent Icom IC-705. 

 

The ELECRAFT KX3  is a classic! It's a transceiver that everyone knows about and it's always been held in very high regard - not least of all because of that stunning SDR receiver. The beauty of the KX3 is that it is perfect for use in virtually any environment - at home as a Base Station, in a National Park on a POTA outing or even at the top of a mountain hunting for SOTA chasers. 

I've had three over the years and when I've sold them (thinking that I've found something better), I always end up buying another one - they're just too good to go without!

The LCD screen on this light, compact radio is exactly the same size as the screen on Elecraft's Base Station K3S and it's especially good outdoors because it's very easy to see even in the brightest sunlight.

The radio has 32-bit variable DSP which works extremely well and you'll find that most secondhand KX3's out there have the optional (and very worthwhile) KXFL3 Roofing Filter installed, (perfect for those who love contesting).

If you're going to use the KX3 as your only radio (and many do), you'll be pleased to learn that there are a range of amplifiers out there which can be hooked up to facilitate making this a great Base Station, not least of all Elecraft's own KXPA100 which can be bought with a built-in ATU. 

I'll never forget the very first time I switched on a KX3 during an outdoor event - I thought something was wrong with the radio because it was stony silent! 

I thought it was broken - but no - it just wasn't tuned into a signal yet and the noise floor was so incredibly low, there wasn't a peep to be heard! That made me smile so much and a friend who was with me (G0UXF) was staggered! He'd never seen a KX3 in action before. It was a bit of a revelation. 

When first introduced it was Rated No.1 and still stands about 12 places above popular radios like the Icom IC-7300 in the Sherwood Receiver Table. In fact it sits above the mighty IC-7610, IC-705 and many other expensive Anans and Flex radios! Even the latest KX4 is below it in Sherwood's performance ranking 😮 It's that good!!

The KX3 that is currently in my possession came with a bunch of extras including…

• KX3 Transceiver (MINT++)
• MH3 Microphone (£90)
• KXFL3 Roofing Filter (£160)
• KXAT3 ATU (£270)
• Palm Paddle Mini Morse Key (£50)
• MFJ 401D Keyer II (£50)
• SotaBeams Bandspringer Midi (£26)
• Sotabeams Guy Set (£21)
• Inline Volt/Watt/Amp meter (£24)
• Manuals, Power Lead, USB Leads, etc.

That’s a pretty valuable collection there and considering that I sold a used KX3 for £1700 last year 😝, I was stunned to see someone accept my very cheeky offer of £650 for this package 😮.  I could easily sell off some of the extras on eBay and bring down the purchase cost even more!

 

So to summarise, the KX3 is still one of the finest receivers available - it has excellent filters and DSP, making it perfect for pulling out the weakest of signals and therefore a potential contester's rig. It's small and light enough to be carried to the top of a mountain and can also be used as your main shack radio with an amplifier. You can attach an Elecraft Panadpter or something like an RSPDX to benefit from a large scope and waterfall on your home PC.

👍👍👍👍👍

 

The ICOM IC-705 is kept permanently in my RuckShack ready for my outdoor activities. It's currently the most advanced portable radio of its kind and has a stunning feature-list which makes it incredibly versatile. Despite its endless capabilities, it costs just £1350 new, which is a bit of a bargain in my eyes. Secondhand models are sometimes available for as little as £800 - a saving of £550 😮

Yaesu have finally dragged their ass out of bed and announced the FTX-F1 and that might be added to my collection, but let's never forget that Icom was there first (4 years ahead of time)! Without the magnificent 705, Yaesu would probably still be selling the FT-818!

I've heard that the new Yaesu will have 4M but I'd bet my last penny that even though they've had 4 years to consider how they're going to beat the Icom, they will still be behind the 705's massive feature-list. 

They did the same thing with the FT-DX101D (vs IC-7610). For those interested in a 705, the lowest secondhand price I've seen is £799. That's a hefty chunk of money for many people, I know, but you'll not get a better All Band, All Mode, Portable SDR.

Many people cannot get past the fact that this is a QRP radio, but the truth is, the IC-705 could very easily be the only radio you ever need. If you're a QRO guy, simply add an amplifier and you've then got one of the most advanced and most feature-rich base stations on the market! Just read the full review here.

👍👍👍👍👍

 

The HERMES LITE 2+  and its matching software, cannot be matched at this price-level. Nothing comes close!  It's absolutely outstanding and you don't fully appreciate how good it is until you have used it alongside some pretty darned expensive rigs.

The HL2 not only performs well, but it gives operators the software that they dream of : THETIS. It's fully customisable and is constantly being updated in response to user suggestions and requests. There's not much that you can't do with Thetis and best of all is the stunning noise-reduction! 😮

All this outstanding performance can be had for as little as £200 if you buy a used HL2 or £350 if you buy new (with carriage and taxes). It beggars belief! Every ham radio enthusiast should have one in their shack.

Needless to say, the 5W power output will be a stumbling block for many people, but a reasonably priced amp will sort that out. Personally, I have no issues with running low power and actually like the challenge, but I do understand that many people prefer to run QRO. 
 

Lashing out on a 100W amplifier can soon ramp up the cost of this outfit - that's true - but there's lots of cheap 50W amps out there for next to nothing, and some are really quite good! I have an MX-P50M which I can highly recommend. I only use it up to 25W and it works really well, putting out a surprisingly clean signal. For operators with higher level licenses, 50W should be more than enough to get you around the world! I spotted a Neptune 50W amp the other day for £165, but it had already sold before I could get a look-in.

The only thing the HL2 lacks is a tuner, but I am aware of one guy (Larry, WR9R) who has actually built one into his HL2 enclosure using one of the Chinese Auto atu PCB's commonly found on eBay. Here's a link to his post. I take my hat off to him - it took some effort!

Personally, I use a cased ATU-100 that I bought at a rally for £35. I guess I could follow Larry's lead and transfer the innards to the HL2, but I probably won't bother - this unit sits neatly next to the HL2 in my shack. I bought one of these previously from eBay and when I unpacked it, it was DOA. Needless to say, I opened this one up in my car before leaving the Rally and it was all fine. They're a cracking little unit if you can get one cheap enough, but bear in mind that it needs a full 5W to tune and my HL2 doesn't quite produce that on every band.

For the newbies amongst us, the tuner always goes just before the antenna, so in this case, it would be RADIO-AMP-TUNER-ANTENNA.

I've said it many times before - I like to use a computer as part of my radio hobby, so the fact that the HL2 is a tiny remote box with no screen, no buttons, dials or switches, is fine by me - I'm totally relaxed using a mouse and keyboard. And that brings me to my next plus-point about the radio - it is operated remotely at all times!

You can access the radio from virtually any computer or tablet, whether at home in the shack, in the bedroom, in the garden or away on holiday. Nine times out of ten though (especially in the Autumn/Winter months), I'll be sat at my main Desktop PC with a large hi-res screen in front of me, a full-size keyboard, wireless mouse and a USB microphone. The large computer screen provides all the real estate for Thetis, Logging software and a Notepad. 

My choice of microphone for use with this setup is the award winning Elgato Wave 3. It's a peach of a microphone and perfectly suited to human voice. It works really well in modulated modes or sideband, with a near perfect midrange pickup. These normally cost around £150 but (as usual) I got mine for around half that price from a podcaster on eBay. One of the reasons I searched for a Wave 3 was that competing mics in this price-band didn't have an onboard MUTE button and there were reports of other mics being prone to hum if touched.

To be fair though, virtually any USB mic will work pretty well, including the microphones built into your laptop or tablet. Sure, they won't give outstanding results, but they'll get you on air making contacts!  You can of course use a regular fist-mic plugged directly into the radio if you prefer, but you need to have the HL2 PLUS for that, because the vanilla HL2 has no microphone socket.

So in conclusion, the HL2 is a must have radio in anyone's shack! For a couple of hundred quid, you'd be crazy not to get one. If you're a bit of an experimenter, this is your dream radio!

👍👍👍👍👍

ICOM IC-7100  Oops!! I forgot about this one! It's another one of those amazing all-rounders that many people overlook. It is unique in that it's the only 100W radio in the world (to my knowledge) that covers HF (160M-10M), 6M, 4M, 2M and 70cm, plus DSTAR!

It is perfectly suited to be used as your Base Station, as a mobile in your car and even as a Field Day or POTA radio. Incredibly versatile. I fitted an IF-OUT to mine to provide me with a Panadapter. You can read my comprehensive review here. You can usually find a minter for around £700 or less.

👍👍👍👍👍

Thanks for visiting the blog! It would be great to hear from you in the comments below...

73, Tom, M7MCQ.

QUANSHENG UV-K5(99) CEC 0.51

WHEN CHEAP DOESN'T MEAN INFERIOR!

I think everyone on the planet has heard of the Quansheng UV range and that's down to the radio's ability to transform itself into something which far exceeds its original design spec, thanks to the availability of various firmware options.

The UV-K5(99) is one of the latest iterations and can be installed with any of the following firmware options to suit the user's requirements...

STOCK Firmware:

The radio features a standard frequency range of 50 MHz to 600 MHz for receive (RX) and offers selectable transmit (TX) ranges of 136–174 MHz or 400–470 MHz with support for AM and FM modes.

EGZUMER Firmware (v0.22):

Experience a frequency range from 18 MHz to 1.3 GHz with support for AM, FM, and USB modes. This firmware includes advanced features such as a spectrum analyser, an AM receive (RX) fix, battery percentage display, additional frequency steps, and configurable button functions for a comprehensive radio experience.

IJV Firmware (v3.40):

This firmware supports a frequency range from 15 MHz to 1.3 GHz with support for AM, FM, DSB, CW, and WFM modes. It is optimized for a wide range of frequencies, ensuring robust performance. Advanced features include transmission in emulated DSB mode, stable SSB reception, SATCOM boost, CW beacon, TX modulation indicator and an S Meter.

CEC Firmware (v0.51): (My chosen option)

In addition to a broad frequency range from 18 MHz to 1.3 GHz with support for AM, FM, CWN, CWF, CW, and SSB modes, plus an internal HF expansion board (IOTCU SI4732 v2.1) and an upgraded RF choke in single antenna configuration, allowing reception (RX) on HF frequencies from 0 MHz to 30 MHz in AM, FM, LSB, USB, and CW modes.

SI4732 PCB HF Modification

Adding the HF expansion board is a pretty simple task if you can solder with confidence and there are plenty of videos on YouTube to take you through the process. Some people even go to the trouble of fitting a secondary antenna socket purely for HF, but I'll leave that for braver souls - I'm currently happy to swap over to a telescopic when required.

To be honest, I don't use 2/70 that much and I already have 3 handhelds to cover VHF/UHF, but none of them provide such an amazingly wide reception range and none of them cost just a few quid!!  If you buy your Quansheng from AliExpress along with a SI4732 Mod PCB, you'll pay next to nothing for a very capable HT.

The aesthetics of the radio are personal and I can understand why some people prefer the appearance of the (8) over the (99) because of the 4 faux bolts around the trim on the older model - they look pretty cool and I think it's a shame Quansheng didn't retain that look.

Having said that, aesthetics are not the prime reason for buying one of these radios. People buy them because they're super cheap and have features comparable to incredibly expensive radios like the Kenwood TH-D74/75, (which also has HF Receive). Sure, there's no Digital modes, APRS or GPS, etc, but neither is there hundreds of £££ being spent. These things are at the price-point where you can just leave one in your car's glovebox!

In practical, everyday use, the Quansheng works exactly as you'd expect any 2/70 to work. It has comparable output power to the big manufacturers and for local rag-chewing, it works a treat. If you're within reach of a local repeater, happy days!

The display is nice and clear, with a useful amount of information and it's pretty easy to work out how to use it without even picking up the manual. When you switch to HF mode (Long Press 0), then you have to learn more keyboard shortcuts...

 

My only criticism of the radio is the tuning method - I'd much prefer to be able to use the rotary dial to change frequency or run through memories instead of having to push the up/down buttons. Having that lovely big dial just for volume is a waste.  Oh, and I wish it had the 500Hz step size. So many HF operators seem to use it these days, that it's annoying when radios don't have it. The sensitivity and selectivity of the UV-K5 is err okay - it's not gold standard obviously - but it's perfectly usable. 

The speaker is loud enough to be heard in noisy environments, but the audio is very much on the 'thin' side. Given a good strong signal though, human voices are well presented - for example if you listen into BBC Radio-4 on FM, it's excellent! There's a 2.5mm headphone socket for when needed.

Battery size is a reasonable 1600mAh and is light and slim. How easy it is to get a spare battery, I'm not too sure, but at these prices, it's probably worth buying a second radio!! A desktop charger is included in the price, which is always nice to have.

So overall, I don't think you can go wrong with one of these. They're a no risk toy - if you get one and don't like it, sell it on - you won't lose money!

73, Tom, M7MCQ