CB to CW PART 2

 In a previous post, I briefly discussed a way to convert an AM-only crystal-controlled CB radio into a 10 meter QRP CW rig with some additional features. Now that I've discussed the theory, I've written this post to track my progress and give you some information should you want to do the same.

My HUGE Pixie Project

 After the failure of the Paraset Pixie, I decided to give up for a bit on any Pixie-related projects. I was frustrated, and rightfully so. I more than likely got a dud but for as cheap as they run, there's not much of a loss there.

However, one does have to appreciate the simplicity of the Pixie circuit. You can spend hours and hours on research, but it all boils down to a simple direct conversion receiver paired with a simple CW transmitter. The work is placed on the final amplifier transistor, as this functions as the power amplifier in transmit, and acts as the mixer on receive. Clever, isn't it? You can see the idea here from the RU-QRP group:

Unfortunately, the Pixie is an abhorrent choice of QRP radio to use. It's crystal controlled, meaning that it lacks frequency agility. The choice of direct conversion on receive leaves the pass band wide open as a barn door, meaning that QSOs will be several kilohertz above and below your spot frequency. The variable potentiometer only helps up to a point. However, this doesn't mean that it is automatically destined for the trash bin. 

Pixie Sixtie (Part III): Harmonic Suppression

 Today I'll discuss a filter that is imperative to have so I can use the Pixie on the air. I'll cover two types - a low-pass and a band-pass, and explain why you may want them on your project.

Pixie Sixite (Part II): The Passive Audio Filter

Today I want to discuss an imperative add-on for the Pixie Sixtie I'm building. This should also apply to any other Pixie kit or similar QRP kit with poor front-end filtering and a wide passband.

Pixie on Sixtie (Part I)

In the 6ish years I've been a ham I have not once touched or operated on 60 meters. It is the only HF band that is unexplored territory for me. That being said, 60 meters may be unappealing to many hams as it was for me. You're only limited to 5 channels with 2.8KHz of bandwidth, mode choices of SSB, narrow data modes such as PSK31 or CW, and a maximum power limit of 100 watts ERP. Not very appealing :|

NightFire Electronics

A few days ago, I thought that I'd make another purchase off of AliExpress again. I went to the store and picked up a prepaid Visa card since that's what I used last time, only to discover that it was only valid in the US. Dang. Well there went $50...

Along Came Etsy

Now I know what you're thinking...why would you ever shop on Etsy, Owen? What do they have on there that's even remotely close to ham radio? 

Well they have a lot actually. Hams are making things from antennas, LED signs, kits, apparel...the list goes on! What a great way to let the ham community shop for items while giving back to their fellow hams and their families! I might start making antennas and selling them on Etsy, actually.

Since I couldn't buy a Pixie kit on AliExpress due to my dilemma, I decided to go find another Pixie kit. I couldn't use eBay because they don't accept prepaid cards and Amazon just wouldn't recognize my card period. So I got to looking at other sites and Etsy came to mind. Sure enough, one supplier - NightFire Electronics - was one of the first seller choices. And right there it was - a 40 meter Pixie kit waiting for me to put it together. So I ordered that along with an audio Morse Code practice oscillator as another building activity.

The Waiting Game and Thoughts

I placed my order on October 26th and according to USPS, my package should arrive on October 29th - that's a pretty quick turnaround considering that NightFire Electronics is in Florida, which is continuing to clean up after Helene and Milton.

Despite this, my package arrived in a cute cube of a box. Nothing too grand, but sometimes the best things in life come in small packages. I went ahead and unboxed my pack of goodies and sure enough, the two kits I had ordered were provided as promised and promoted. 

The Pixie

To my surprise, the Pixie isn't that much bigger than the generic ones you get off of eBay. The PCB is a bit thicker and seems a bit more robust too. 

This one still uses varactor tuning but I have learned a lot about varactor tuning in the past few days. Basically, when a diode is placed backwards (cathode side towards the voltage source, anode to ground or negative source) it exhibits a phenomenon known as junction capacitance. As the voltage is increased or decreased, the capacitance varies. There are specific diodes that serve as varactors such as the MV209 used in the MFJ Cub, but common 1N400x series will work just fine if used as fine tuning, such as RIT. The Pixies use these diodes for varactor RIT tuning, which provides a small variable capacitance and receive offset of between 700 and 900Hz - perfect for copying CW! If you really wanted to, you could substitute an actual varactor in place of this to have a wider tuning window. You'd just have to adjust for offset every time you keyed up.

I purchased the Pixie kit with a base frequency of 7.030MHz. Now, I could keep buying up crystals and swapping them out to change frequencies, or I could use a variable capacitor to shift the frequency by about a kilohertz or so. Your mileage may vary, especially if you're using an HC49/U (tall-cased, more pull) versus an HC49/S (short-cased, small pull). Also, don't permanently solder in the crystal. You can use pin headers to easily change out crystals or VXO modules.

The Pixie did not come with any output jacks. Rather it was provided with four 2-pin screw terminal. This shouldn't be a problem and the input/output jacks should be relatively easy to come by. I already have tons of BNC panel mounts, a panel mount DC barrel jack, and several 3.5mm jacks.

This Pixie has an additional capacitor in parallel with the low pass filter inductor. You can add a value of 130pF to further attenuate spurious emissions, although the schematic says that this component isn't used. I find it to be absolutely necessary, as I have been thoroughly analyzing the ineffective output of the Pixie's filter. This capacitor helps significantly reduce the second harmonic to a dip, which thereby reduces the third, fourth, etc. by more than -25dB or so from the fundamental. It works because it is resonant on or near the second harmonic, which is 14MHz.

Code Practice Oscillator

While I liked my Arduino Nano CPO, it just wasn't small enough to tote around. I ended up purchasing another oscillator kit based on a twin-T oscillator configuration. This is fed into an LM386 to amplify the output, which is a sine wave at around 700Hz.

Depending upon the kit you have, you can change a resistor in one of the T-networks to change the tone. So if you're not comfortable with 700Hz you can experiment with resistor values to see what you like. As an added bonus, I'm thinking of adding on an Arduino to the key input to generate random words and phrases. A digital pin fed to an optocoupler and fed into the keying input should do the trick just fine.

Conclusions

Simply put, I will most definitely be buying more things from NightFire. I feel that they are reasonably priced and are dedicated to making electronic kits accessible for all. One kit that looks cool and is easy to assemble is their ghost detector. Whether or not it works...well, that's for you to decide. In practicality, it is an overly-amplified LED detector that picks up electromagnetic changes nearby. 

That's not the only things NightFire offers. They offer everything from amplifiers, Arduino kits, capacitor/resistor kits, and so much more! So if you're looking for some fun kits to build either to pass the time or practice your soldering skills, look no further than NightFire Electronics!

QYT KT-8900 Kaput???

 Back again with a 6 month review and update of my QYT KT-8900.

I have to say that I am thoroughly impressed with this radio, despite it not reaching the 25W promised output. I can still live with that though! I can easily access the repeater anywhere in town with a simple mag mount antenna. The microphone issue never really seemed to be an issue in the first place. However, the mic may have a different problem associated with it now that I've had it in my car for a bit.

The Main Issue

Here's what I think...

On cold days, when my car is not started, I can climb in and key up the radio. However, as the environment around me warms up, the microphone stops working. I can key the microphone which transmits a non-CTCSS carrier, but it never seems to transmit the CTCSS code. When I let the PTT up, it transmits the squelch tail properly on the repeater.

Now, it doesn't always work when it is cold, and the workaround is to twist and bend the mic wire every which way in order for it to transmit. I've narrowed down the problem to one of two places - the mic cable or the microphone itself. So I'm planning to order a different styled microphone in the hopes that it will solve the problem! I highly doubt it is within the radio circuitry but that isn't out of the question quite yet.

Here's what actually happened...

So we have two cheaply-made radios here - a Baofeng UV-5R and a QYT KT-8900. One has a very weak and insensitive receiver, meaning that every time I key up my QYT very close to the Baofeng (in this case, INSIDE of the car or a VERY large Faraday cage), I'm essentially overloading the Baofeng's receiver. The UV-5Rs do suffer from this design flaw and are known to have crappy receivers if overloaded. They just become so deaf they're useless. Due to the receiver sensitivity being quite finnicky, you just kind of get what you pay for. This is more so the problem - the UV-5R is so overloaded by the mobile radio that it doesn't even pick anything up, only the repeater's squelch tail. 

Problem solved - no mic needed here!!! Phew!

Again, ham radio problem-solving at its finest, ladies and gents!

How's it going?

Well, to be honest, the KT-8900 does the job just fine, even at around 10 watts! CHIRP just released another stable version a few days ago and it appears that I can finally customize the settings without a problem.

I've attached the radio via Velcro just below the steering wheel where it is out of sight from view. The Velcro does a much better job than Command strips at fastening, securing, and holding the radio. 

Again, my recommendations still stand. Turn down the power pot so you're only at around 10 watts on high power or replace the final transistor. The first is the easiest option by far, and only takes around 5 minutes. It is a very touchy adjustment so adjust in tiny increments.

So, after almost half a year, I'd still recommend this radio. 

A Life Update as of Fall 2024

 Hi everyone...

Realistic TRC-412 Emergency CB

It's an emergency CB radio! How ingenious! Guess who bought one? ME!!!

A Fun CB and/or 10M Project

 Back at it again with CB radio...but this time, with a twist.

The PeaNOT: A 74HC04-based QRP Transmitter

As a computer scientist, we deal with several ICs that serve many purposes. Some are microcontrollers. Some are logic gates. Some are just...rather interesting. There's one IC in particular that has its uses as a minimalist oscillator or transmitter with at least 6 components: the 74HC04, the legendary CMOS inverter.

My Thoughts on Citizens Band

 So I'm not one for making opinion posts...but...

I want to make it clear - CB radio is what got me into ham radio. I remember going down to clean out our basement one day when I was about 10 and I stumbled upon a bluish-grey metal box with a mic coming out of it. It was a Roadmaster (Royal Sound) RE4000 CB radio - and it changed my life forever. And for all you CBers reading this post - I hope that I can speak for all of you...

Hearing the Dead

Satellites, that is... 

Miles and miles above the ground, thousands of metal bodies with specialized instruments orbit our blue and green marble of a world, taking photos, surveying weather phenomena, and even providing amateurs with extraterrestrial repeater service! 

With that being said, I can't emphasize how many orbit the earth - there are so many that concerns have been raised about the threat of space debris falling from the sky. In recent months, space debris from old satellites have fallen from the sky, and in rare but not impossible instances, they have ended up in someone's home. 

However, some of these pieces of space junk have been found to be fully alive! After 40, 50, and even 60 years, some satellites just spring back to life. Below are a few examples of ones I've found - and heard!!!

HamDashboard de VA3HDL

 Jason, KM4ACK, has done it again. He's shown another really cool ham thing on his YT page - a ham-friendly dashboard!

If you're looking for a way to have ALL your ham radio internet-linked things at your fingertips, look no further than VA3HDL's Ham Radio Dashboard. All you need is a web browser to get started.

A 1980s Rarity: Montgomery Ward's GEN856A VHF/UHF scanner

I remember one time when I was young where we had to take shelter during a tornado warning. As a Midwesterner, you get used to stuff like this. When we were huddled in the basement waiting for the storm to pass, I remember my dad having a black box in his hand, with a grey top and two antennas sticking out from it. It looked like an old walkie-talkie, but in fact, this box would end up changing my life forever.

Creating an RoIP Node for My Community

 One of the things I thought about when I became a ham was the other hams in my community. I got licensed with about a dozen other people who all have at least their Technician's license, and many of them live in the same community as me. I have always wanted to do a project for the ham community around here, and I believe I might have a solution.

Motorola SM50 for Ham VoIP

Along with my Maxon SM4450, I was given a Motorola SM50 GMRS radio. I actually thought that it didn't work at first until I realized that the power leads were installed backwards on the SAE pigtail! I can confirm that it now works and puts out RF quite well. 

Well, after lots and lots of trial and error (and with the confidence I gained through rebanding and reprogramming the 4450!), I got my Motorola SM50 UHF radio realigned on 440MHz! After modifying the .MDF file for the RSS software, I was able to program it to 440MHz to 480MHz. Of course, I won't need all this bandwidth as I'm only allocated to the lower 10MHz!

I programmed this radio using a CP2102 connected to the radio, and I used DOSBox to emulate DOS. It is recommended to use an actual DOS computer, but I found this method to work best for me, despite it having lots of hiccups along the way. I did find a workaround for it though!

Putikeeg Key Review - Your first CW key

 When I first got in to ham radio, I never thought too much about CW. At the time, I was glad that the requirement for copying Morse was tossed out. As I've gotten older and more seasoned in the hobby, I've come to appreciate CW and it's beginning to become one of my favorite modes.

Hams who are serious CW enthusiasts will spend hundreds, and sometimes thousands, on refined Morse Code keys. As someone who is more of a rudimentary kind of person, I prefer simplicity - the less adjustments needed, the better. Over the years I've 3D printed a key and crafted one from a clothespin. Both worked, but lacked the charm of a key like a J-38 or an old mini Soviet key.

In recent years, cheap yet promising keys hit the market from a manufacturer by the name of Putikeeg. These keys were described as being crafted from 6061 aluminum and came in straight key and paddle configurations. While I really wanted a paddle, I had some money set aside for a CW straight key. So, I took the plunge and ordered one from Amazon.

And, here is my review.

UHF APRS: I think I may have a solution!

 Hello there, just a short tidbit I wanted to share.

A Month with the QYT KT-8900

 Well it's officially been a month or two since I first received the QYT KT-8900. As promised, I would like to do a one-month check-in on this rig!

IT'S HERE! IT'S HERE! A weather update, that is...

 Ever since I was little, weather has fascinated me, between snowstorms and tornadoes. I've had my fair share, and with the recent 3-day outbreak in Iowa, Nebraska, Kansas, and Missouri, that fascination has reignited in my soul. In fact, one of the reasons I became a ham was to help out if the weather ever took a turn for the worse.

The Ten Minute Transmitter

 Decades ago, a ham by the name of Steve, G4RAW, conceptualized a CW transmitter in a magazine article capable of putting out up to 1 watt of RF power over the air. It was so barebones that even the newly-licensed amateur, with little to no experience, could throw it together, tune it up, and possibly make a QSO in a matter of minutes. No, not hours - minutes. 10 minutes to be exact. This rig is called the Ten Minute Transmitter.

Listening to DX AM stations

Yes, including transoceanic ones!

Recently, I picked up some TA7642 chips from Amazon on a whim. Originally, I wanted to make a shortwave receiver with an external BFO for a QRP project, but I learned that these chips only worked up to around 3MHz. However, not all hope was lost.

An Interesting APRS Experiment

Things have not been going as planned, especially since my Kenwood TK-705 now lies in pieces and is probably dead. The APC circuit is completely dismantled and I'm not sure if it's worth fixing now. However, not all hope is lost for my APRS adventure.

I recently passed the online SKYWARN training, and they always mentioned the use of ACES while storm spotting - Awareness, Communications, Escape Route(s), and Safe Places/Shelter. I have read that many SKYWARN spotters utilize APRS when they are in the field to relay their position to others to keep in constant contact. In the event that a vehicle would face the inevitable destruction of a severe storm, this would enable search-and-rescue teams to quickly locate the spotter's vehicle. With a few inexpensive items and a DIY attitude, anyone can do this, and if you aren't a SKYWARN spotter, you can use this for other purposes such as a wireless weather station, a standalone APRS beacon, a vehcile tracker, and so much more! If you want to go above and beyond, you could add an entire weather station with temperature, wind speed, humidity, etc. to make your vehicle just like a Tornado Intercept Vehicle. Small disclaimer: I strongly don't recommend driving directly into tornadoes unless you drive TIV-1, TIV-2, or any of the Dominator vehicles!!!

QYT KT-8900: The UV-5R's Mobile Big Brother

I've decided to install a mobile-oriented radio in my brand-new-to-me vehicle. There are many on the market right now, but one caught my eye in particular:

This is the QYT KT-8900 VHF/UHF radio. It claims to run at 25W but let's be honest here, it will only run about 15, maybe even 10 watts. That's still not bad, considering that this is from - you guessed it - China. At just a little under $100, I decided to take the plunge and see how it would perform as a mobile rig.

First-Look Impressions

Initially, this radio had been riddled on YouTube, reviews, and forums with issues right off the bat. The worst of it was the final RF amplifier. The final is heavily overdriven in this application and normally, it would run at 6 or 7W max output. This works, however, these radios don't use heat sinks on the final, rather, they use a piece of "thermal foam" entrapped under a piece of brass. Despite having a fan on the rear, this is not enough to cool the final if the SWR happens to be mismatched. Some models don't even have a fan, so overheating is expected anyway. So, my first suggestion if you purchase this is to take the manufacturer's "heatsink" off, add a very minute dab of CPU compound and place an aluminum heatsink on top. Also, use a properly tuned 2m or 70cm antenna. Problem solved, heat dissipated, no SWR overload... for now...

Next, there have been complaints about this radio not being compatible with CHIRP. The supplied QYT software seems similar to CHIRP and it may do just fine with me. However, it is imperative that you install the PL2303 - this is the driver you need to program with the provided cable. If all else fails, it will program manually just like the UV-5R via the keypad. If you're on Mac or Linux, CHIRP will be your only software option.

UPDATE (10/22): It appears that CHIRP now works flawlessly with the radio I have. Previously, I could not edit any of the customized settings, such as the power-on message. This was due to an invalid BCD. In the 10-20 update, CHIRP appears to have resolved this problem and I can now adjust custom settings. Despite the model still being labeled "experimental driver," I think it's safe to say that CHIRP now can communicate with my radio without an issue.

Of course, if you'd rather, you can build your own using a <$5 CP2102 and a 3.5mm stereo (TRS) jack. The pinout is simple and building one is just as easy. The tip is TxD (RxD on CP2102), ring is RxD (TxD on CP2102), and sleeve is ground. If you find that it doesn't work, try swapping Tx and Rx pins. Some modules may be wired backwards. As an added protection against power cycling during programming, 10K resistors can be added between the serial pins and ground.

I've also heard that the included microphones with these have very poor audio quality and I have found a minimal amount of modifications to fix this. The solution, obviously, is to use a different microphone. I suggest using Kenwood's line of RJ-45 mics - this should solve the problem. For a better money saver, there is an SMD resistor (value 332, 3.3kOhm) that can be lifted from one pad or, as a better solution, removed completely and replaced with a 5K pot, as shown in this Facebook post here (click the photo for better resolution):

One other issue I've heard is that these don't work the best as mobiles and will pick up everything from vehicular EMI/RFI as well as pager systems if you town uses them. The obvious answer to this, in my experience and opinion, is to use as many ferrites as you can. Wrap the DC cable in a snap-on ferrite about 3 or 4 times and place a few on the antenna coax as well at the radio end. This should mitigate some issues, but your mileage may vary.

The issue of having only one 3.5mm jack appears to be resolved. It was previously mentioned on various forums and sites around the internet that this radio lacked an audio out jack. The rear one, at least on mine, is indeed an external speaker output which will mute the top speaker. The front is the programming jack. 

Lastly, if you need to replace the final for peace of mind, or if you experience a thermal burnout (aka, releasing the magic smoke demons), this page details the how-to. It's not entirely difficult and the part I'd replace it with would be this one at DigiKey. It is better suited for this radio (16W output vs only 6W output) than the claimed factory one and is well under $10. For now, I will put a modified heatsink on the factory chip with a dot of CPU paste as I mentioned above and turn down the middlemost potentiometer to achieve a maximum of 10W output, as seen in the screenshot below. This should save the final until I can replace it with the better one. And for reassurance, the Leixen brand radios of the same size also utilize this much power output.

Despite this, I purchased one just to see how bad (or even good...) these are. I do have high hopes, but we'll see if the product delivers. Have they improved quality control over the past 10 years or will it still scream "Made in China?" 

So here we go - my review.

My Thoughts

Instead of using a UV-5R as a mobile, why wouldn't I use a mobile-specific radio that is about the same size and can push out around 10 or even 20 watts? I think I will also hold on to my UV-5R as an HT and use the TK-705 (IF I EVER GET IT FIXED!!!) for APRS since it's pretty well scrapped. The final stage on it and APC stage are both completely useless at this point so I might have a few ideas to push some watts out.

Here's what I like about the 8900, according to the claims:

• Small profile - easy to affix anywhere in your car or truck. For extra security, you could even put it beneath a seat out of sight! It's literally as big as a slice or two of bread.
• Ease of use - If you started off with a Baofeng UV-5R, you'll have no issues moving to this as a mobile radio - they're the same thing and have the same menus and interfaces!
• Dual or Tri-band - If you use 220MHz or the 1.25m band, you'll be happy to know that this is also offered as a 2m/1.25m/70cm model, though 2m and 70cm is plenty active around my area.
• Cooling fan - After the final stage complaint, I'd say the company(ies) tried to fix the issue, but in any case, a cooling fan is a must. A simple modification can be found on the link to replace the final above.
• CTCSS, DCS, DTMF, etc. -compliant - you can't really do repeater work without this!
• Safe-for-car power draw - Rated at 4 to 5A max on transmit, some claim at most 7A. The average load a 12V auto outlet can hold is around 10A (an average of 12V @ 120W. At least that's what cars I've been in can handle...). On standby, expect no more than 200 or 300mA.
• LOUD audio output - Despite it's small size, the receiver has an excellent audio output via a ~2W top-mounted speaker.
• Built-in FM radio - Works from 65 to 108MHz. Good for out in the field or if your car radio doesn't work well.

As with any radio, it also has it's flaws:

• Poor RF final choice - strictly speaking, constantly overdriving your severely underspec'd finals will wear them out within months or even weeks of high-power usage. I'm not really convinced the RF engineers (if there were any!!!) thought about this. The better replacement is around $7 on DigiKey, so that's a plus.
• Instruction manual - Good ol' Chinglish - even harder to learn than both Mandarin Chinese and English combined!!! Just look up some YouTube tutorials.
• SMD technology - Okay, this may not be a complaint, but I find SMDs very tedious to work with if something were to go wrong.

In all reality, that's all I can say about this radio! As you can tell, the pros outweigh the cons for me. Let's unbox and see what is inside...

Official Unboxing

I ordered the KT8900 from Amazon for $80.99. Included, it claims to have the radio, the DTMF microphone, a 12V cigarette lighter adapter, the mount and hardware, and a programming cable.

Right now, I plan on putting this in my new vehicle that I will be buying soon, but instead of permanently damaging the plasticized interior with screws, I would like to mount the bracket with a softer solution, namely, heavy-duty Command strips or Velcro. This should hold the radio up pretty well and shouldn't have a problem with any road vibrations or daily driving. Since this car has a bench seat, there is a good-sized crevice up front that would house this radio pretty well! Less than a foot away is the 12V outlet. In addition, I will be using a standard magnet mount dual band antenna.

Unboxing it, I was pleased from the start. The radio and all its components were packaged nice and neat. I was impressed with the size and I must say it is very compact!

I did want to open it to see what I was dealing with regarding the RF final. Turns out, it is a Mitsubishi RD07MUS2B MOSFET, but the NXP chip I mentioned should work just fine, and I will eventually get one later on. For now, I'll leave it as is, but I will be installing another heatsink. Yes, it did come with the cheap foamy stuff. The small micro-sized cooling fan provided will work just fine.

The receiver is quite crystal clear and it does have a relatively loud speaker, which is perfect if someone is driving at highway speeds. The microphone does seem relatively well built, but don't expect it to survive if it falls on the ground. The lighted keypad is perfect for nighttime driving and provides excellent visibility. The DTMF pad is soft and squishy, and does not seem too terribly hard to press. The PTT button, though clunky, works well. I am unsure about transmit audio since I didn't get around to testing it that far.

The controls are very sharp and I'm sure that this radio will last quite a while. As long as it is taken care of, I expect it to last me for as long as I need it and then some. And hey, if it doesn't work out in the car, I can always make a portable VHF/UHF station with a spare metal ammo can I have!

Final Thoughts

I was moreover impressed that the instructions were in full English with very little typing errors! It's nice to receive a manual that you can understand. Perhaps the QYT model has increased in the quality control department, but we won't know until I take it for a field test. I'm very positive and I'm sure this will do just fine for me.

I really overestimated the size of this thing - it truly does fit in the palm of my hand and I do not have large hands! It is very lightweight but durable enough for vehicular, mobile use with the frame being made out of pure metal. The loud, crisp speaker only improves the clarity of the received signals and I think that this one is a keeper for sure. Replacement parts are quite easy to come by as well, making this radio less of a headache to own.

I now need to make a Wal-Mart run to get some cable clips and Command strips. To save the final, I will probably turn this radio down to about 10W maximum output, which is sufficient for the stock final. The Leixen VV-898 mobile radio has this much power output and I've heard that people can hit repeaters with them over a fair distance away with even a cheap, mediocre antenna.

So, in conclusion, is the QYT KT-8900 worth it? Yes, absolutely. For the beginning Technician and/or those familar with the Baofeng, purchase one of these and use it until you can get a more reputable radio such as a Yaesu, Icom, or Kenwood. Who knows? You may still end up using this full-time in the end!

UPDATE (5/14): I have the radio installed in the car and so far, I am very impressed! I have a little bit of an occasional pop or crackle in the speaker that only comes on if the car is in motion, but it doesn't bother me at all. A filter capacitor on the 12V lines may remedy the issue, such as 10pF for high frequencies or 0.1uF for low-end frequencies. Reception is still clear and the volume is more than comfortable in an automobile setting. I am using a cheap mag mount antenna and I can hit the repeater anywhere in town. I did turn down the power to a value of 10W I assume, but I won't know until I get some more refined test equipment. All I know is that the fan doesn't come on when the radio is in high power for an extended period of time and there's no smoke or burnt smell, so that's a good sign!!!

UPDATE (5/21): Nowhere near 10W originally - more like 0.5W!!! I did turn it up to around 10W now, however, the fan does kick on. I do not really notice power loss as the transistor heats up, and I really don't think the transistor gets stupidly hot! So I think we're good!

To close, I would like to recommend a few things about this radio:

1. MITIGATE THE RF FINAL ISSUE - First and foremost. Either replace the heatsink, replace the module, turn down the power, or do a combination of these. You'd be very sad if you destroyed the final and had to spend a long time replacing it!

2. Keep it out of the sun - Don't put it on the dashboard of your car. Put it beneath a seat, down by the center console, under the arm rest - just as far away from sources of sunlight heat and UV as you can. Heat is the number 1 culprit of failure in this application.

3. Join support groups on Facebook, Groups.io, etc. - Just like the Baofengs, there is limited factory support. Consider joining groups and doing your research on these rigs. Facebook has at least two or three groups dedicated to the QYT line of radios.

4. Use a tuned antenna with an SWR of at most 1.5:1 or less - This will also help keep the radio operating for as long as possible by putting less stress on the final.

If you follow all of these pieces of advice, there's a good chance you'll keep your radio safe from harm for a long time, and this goes for all radios! Truly, the KT-8900 is an excellent base radio for new techs or for the ham that just wants an easy, inexpensive base radio. 

That's about it from me for now! I'll see you in the next post!

Beware the Dangers of eCommerce

Good morning all, I wanted to post a little cautionary message.

Last evening, I was attempting to purchase an M67741L RF power module for the TK-705 I plan to refurbish. I was notified this morning that the seller had closed the sale and took the product down off of eBay for no reason. As you may have guessed, this product would have come from outside of the US. Luckily, no money was lost, but if I had bought it immediately instead of offering a deal, I would have lost out on $20.

APRS Digipeater Update

I am happy to announce that the digipeater project is coming along slowly but surely. I have run into some major hiccups along the way, moreover with the many USB devices I have been using and the poltergeist of RFI.

Maxon SM-4450 70cm Conversion

    A short time ago, I was given some GMRS radios from a local ham friend who was cleaning out his house. One of the radios given to me was a Maxon SM4000 series radio, namely, the SM4450. From the factory, this radio operates from 450 to 470MHz. It was also one of the very first radios to be programmed via a computer and software.

    Unfortunately, I am a ham operator and cannot use the GMRS frequencies legally. I am not licensed to do so and I am not seeking a GMRS license. I am, however, guaranteed a section of the UHF band. In the United States below Line A (see FCC definition), hams are allocated the 70 centimeter band on a secondary basis, running from 420MHz to 450MHz. Hams above Line A must refrain from using 420 to 430MHz, as this is a crucial frequency to the Canadian government. 70cm is unexplored territory for me. I have only made 2 contacts on 2 meters via a repeater and the simplex frequency.

    To open up myself for 70cm exploration, I got the wild, but certainly not impossible, idea to realign this radio to operate in the 70cm band. In doing some rabbit-hole research, I not only found that this was possible, but it is simple too! Unfortunately, 70cm is very inactive around my area, but I'm hoping to change that with this task!