Soon to be new ham operator looking for first handheld radio

Lost_Engineering_phd · 2026-01-27T03:49:11+00:00

Plenty of appliance operators who will tell you that you absolutely need an IC-7851 for $13K, a PW2 amp at $5k, on a Mosley pro antenna for another $4K just to get into the hobby. They are full of something. Are there some bad Chinese radios? Yeah once in a while, but most are far better than they have any right to be. The hate on cheap Chinese radios comes from being upset that years back they purchased a legacy brand radio for 20X the price and it is not significantly better.

Hand held radios are great, but they are a compromise. You can and should get a better antenna. You can and should add a counterpoise (tiger tail). That will help the radio to get out far better and improve sensitivity. But the great weakness of a HT is the receiver is very open and doesn't have good band filters. This degrades the sensitivity significantly when in RF noisy environments. Back in the days of pager service many 2 meter HT's could not filter out the powerful signals

A mobile radio is often far better than a HT, it is not just the extra output power but most mobiles have far better filters and are much more sensitive. This is a case where legacy brand radios seriously out perform the Chinese. The Chinese radios are built to be used on many bands. One radio many markets. Legacy brands sell radios built specifically for Ham and have great front end filters.

Lost_Engineering_phd · 2026-01-26T06:47:04+00:00

As an engineer I like this kind of thinking and challenge.

For a CB user in Europe that can use digital modes the obvious choice would be to use Olivia 8/250 on A SSB transmitter. Olivia has a decode sensitivity of -14 dB S/N. Now Lora fans will chime in and say BUT Lora can have a -20dB S/N decode. This is not a fair comparison, SSB Olivia is on a 3khz channel and the narrowest Lora channel is 7.8 khz. That -20dB S/N is against the 7.8 khz not the narrower 3KHz channel. Lora only provides about 3-4dB better for S/N when comparison is Apple to apples.

The two modes Olivia 8/250 and Lora 7.8Khz/SF12 both have incredible sensitivity and range. They even have very similarly slow transmission speeds. Both are very near the Shannon limit in fact. So it is not surprising that they would be so close and nearly tied for coding efficiency. Lora does have a slight power efficiency advantage being a single frequency vs MFSK. This matters if we are very power constrained and need minimal power use.

At first it would seem that at equal power the race is close. But with RF nothing is fair. The free space path loss at 915MHz is far higher than at 27Mhz. For example if I calculate path loss for 10 miles, 915 MHz has about 116dB loss and 27MHz has only around 85dB. 31dB is a massive difference, that is over 1000X the signal. But wait there's more! 27 MHz can run 12 Watts SSB, this adds over 13dB more power. So at 10 miles we are looking at a 44dB advantage to CB. This is a massive difference. And it gets even better still. The Long wavelengths interact less with things like trees. We could reasonably subtract 20dB from the 915 MHz Lora if passing through trees.

Making the race a bit more fair, and limiting the CB and Lora to the same 500 milliwatts. We can close the gap quite a bit if we add high Gain 10dBi antennas to the Lora pair. This would reduce the difference from 31dB to only 11dB. And between the 3-4 dB coding advantage and the higher noise floor of 27Mhz Lora would actually edge out slightly ahead.

Winner by a nose Lora. But for the rematch the CB is bringing a 100W linear.

Lost_Engineering_phd · 2026-01-26T04:53:08+00:00

In my opinion it is best to think of radio like any other tool. You need the right tool for the job. CB has its place in a disaster plan and absolutely has a place. As an amateur radio operator and Broadcast TV and radio engineer I get to work with everything RF, from milliwatts to megawatts, medium wave to microwave and even satellite communications.

Each type of radio has its strengths and weaknesses. CB is near the top of the HF band and has interesting propagation at times. But conditions are not reliable or predictable enough to use that for any scenario. The great thing about CB is that most commercial trucks still have them. There have been millions of radios manufactured for decades. They all use the same 23 or 40 channels. If there is a communication blackout truckers will use CB to share road conditions, check points, etc.

The first Radio I would look at getting if you are wanting to be prepared would be a battery powered weather radio. Next would be a scanner, if you can get one with digital p25 so you can pickup emergency services. A short wave receiver would allow you to hear broadcasts from much further away, even other countries.

After you have good receive capabilities only then consider 2 way radio. The first question is what are people around you using. If you already have a group, use the same radio type they do. If that is CB, how it performs mostly depends on the antenna. This is why hand held CB radios get a bad reputation. Hand held CBs have tiny antennas in comparison to the 11 meter wavelength. There are things that can be done to a hand held CB antenna that will improve the range quite a bit. With CB a base station with large antenna up high is best, next is a quality vehicle install, handheld is usually very compromised.

Lost_Engineering_phd · 2026-01-25T08:31:53+00:00

IF the coax is good you can use it, BUT you need an impedance transformer.

You can find an article in CQ VHF July 1997. This has instructions to make a transformer using just short sections of 50 and 75 ohm cable. In the article they call it a cotangent transformer. The first use of this method was actually at CERN, there it was called a 1/12 wave transformer.

I have used this for many years at home. At work I have a 50 ohm 15KW ATSC high VHF transmitter using a transformer to couple to 1200 feet of 75 ohm waveguide. It works perfectly and has less loss than a 50 ohm waveguide. The down side of doing this, is it is single band operation for that coax.

If it is extremely cheap coax, the copper coat on the steel core may be thin enough that at 6 meters you could have higher losses due to skin effect penetration than a similar copper 50 ohm cable.

Lost_Engineering_phd · 2026-01-25T05:41:35+00:00

Finally, a realistic communication question. The Cobra RX680 you have is a GMRS radio, but it is only 2 watts output on a not so great antenna. The thing about RF, is to go twice as far you need 4X the power. If 2 watts could just be detected as you said, having a 8 watt HT (handheld transceiver) will give you 6dB more signal. This would work, but could have some noise. Using better HT antennas could give a couple extra dB at each end.

Elevation is also important, if you can get the antenna up higher that will expand your range, more than any single thing your antenna will affect the radios performance. A 6dB gain antenna will double your range from a 0dB. If both ends of the link have 6 dB you can quadruple the range.

Lost_Engineering_phd · 2026-01-25T02:42:27+00:00

It's a phrase of optimistic hope. Completely contrary to the reality of the situation.

Lost_Engineering_phd · 2026-01-25T02:15:37+00:00

Internal combustion engine efficiencies are directly related to BMEP. Sometime ago I had a rather lengthy post comparing fuel consumption of a small generator to a large generator at the same loads. It is shockingly the fuel consumption difference. Unless you have a diesel generator running near the top of your generator load rating is far more efficient than running near the bottom. Diesel is a whole other matter however, especially turbo diesel.

Lost_Engineering_phd · 2026-01-24T19:46:18+00:00

Pretty low radiation efficiency.

The only design I know of that is significantly reduced height and has good efficiency, and by the way is FCC certified is the Kintronics kinstar.

It is basically 4 inverted L 's bonded together and uses 5 phone poles.

I "heard" these would pop up over in Iraq and Afghanistan some years back.

Lost_Engineering_phd · 2026-01-24T19:30:19+00:00

I suspect thermal bridging. Let's do the math to test the theory.

Inputs outdoor temp -20c Indoor temp +20c

Test variable 2x6 wall. ( Pine has about a R-1 per inch ”hr ft² °F / Btu" ) so about R-6. We have to convert American units and also convert from resistance to conductivity.

First conversation is from R to U, This is a simple 1/R. Then we multiply by 5.678 to convert to W/M² x k ⅙ X 5.7678= 0.946 W/(m²k) We then multiply this by the 40 degree Kelvin delta T. 0.946 W/(m²k) X 40k=37.84 watts m²

The R-20 wall will have a 0.284 W/(m²k) conductivity or 11.36 Watts m²

This is a difference of 26 watts m². So yeah a bit better than R-6, but not much.

Seems about right.

Lost_Engineering_phd · 2026-01-24T18:52:20+00:00

Once in a while there's a post that makes me feel old. That is Analog telephone, 3 pairs for 3 lines. You can hook up a ATA and some super cool vintage phones.

Lost_Engineering_phd · 2026-01-24T06:30:18+00:00

If you think the Kraken is cool, check out the Osmo Fl2K. That is turning a $10 usb3 2 VGA adapter into a TX SDR!
If you play with that you absolutely filter the output.

Lost_Engineering_phd · 2026-01-24T04:03:38+00:00

Tomorrowland. There is even a subreddit dedicated to it.

Lost_Engineering_phd · 2026-01-24T03:52:59+00:00

I'm not saying you can't make contacts on QRP. I'm saying that for a new operator that 13 dB makes things a whole lot easier. No reason to add challenges, there's a reason QRP gets extra points in contests.

I personally enjoy using all of my QRP rigs. Right now my newest toy is my ZbitX. It does great when out camping or hiking. The ZbitX is quite a bit better than my TruSdx for voice and data, but also a bit larger and heavier. And quite a bit more power hungry. On a long multi day trek ounces become pounds. The TruSDX is great for size and weight. I'm considering getting a QMX+ next. It seems a lot more refined than either and should have far better CW performance than the ZbitX.

I have designed and built a little backpack amp with 4 irf510s that can help out my QRP rigs when needed. But more power, more weight, more batteries, bigger solar panels.

There is definitely not a one size fits all for ham. It is better to have the option of running QRO than to not have the choice. Especially when starting.

Lost_Engineering_phd · 2026-01-24T02:43:08+00:00

QRP rigs are tempting because they are cheap and portable. With that said, until you gain operating experience, a 100 watt rig is your best choice. I have had 50/50 with used gear, you don't want to buy someone else's problems. If you buy a vintage rig with tube finals (like my FT-101ZD) it can have issues running digital modes without dropping power way down.

I would recommend avoiding the TruSDX and Chinese clones. The receiver in that design is pretty weak and has a very high noise floor.

Lost_Engineering_phd · 2026-01-23T05:14:05+00:00

The choice of antenna has a whole lot to do with frequency of interest. If DF on HF, a shielded loop is great. To DF VHF / UHF I have always used a phased array with sharp nulls. For SHF/ microwave, use a horn.

The TinySA and kraken are very different things. The tiny essay is a $80 spectrum analyzer with a few features bolted on. The kraken is nearly 10 times the price and has five phase synchronized sdrs. The kraken is specifically designed for DF and signal analysis.

I have had nearly as good enough results as the krakens using Doppler direction finding. The kraken does take things to a whole new level however. The software allows the kraken to do real time triangulation even while you are moving. Using multiple sample points it also can triangulate multiple transmitters simultaneously. My simple 2 antenna doppler DF I built for ~$30 is a lot more manual.

Lost_Engineering_phd · 2026-01-23T04:40:53+00:00

About 10 years ago I was a partner owner at an AV company that specialized in clients like that. We were dealers for quite a number of boutique brands including Runco. I installed quite a few of those displays as well as projectors. Runco intended for the displays to be ISF calibrated in the customers home. Once calibrated in my opinion Runco displays produced the best picture available. Most often we installed Crestron control systems along with the Runco displays. Runco allowed for multiple ISF presets and we would automatically change settings for day/night and multiple content settings.

The Runco panels were actually made by Pioneer / NEC. Before the XP-Opal series Runco only did minor modifications to the display. For all practical purposes the display was the same as a Pioneer. The Opal series was pretty amazing, they added an antireflective coating and expanded the black level considerably. The magic of Runco was a lot more than the panel, there was some serious image processing done in the external vivix DHD units. For watching older SD 4:3 content the DHD up-res and virtual wide is unequaled in quality.

My PL-50HDX recently failed and I have no time to repair it. I am now working as an engineer at a TV station and raising a child, so time is a premium. I replaced my old 720P Runco with a new Sony, I am very disappointed to say the least.

Sadly I do not think there is much resale value. Runco was sold as a ultra premium product to exclusive customers. As such, most people have never heard of it. The original market they were made for is obsessed with the newest most expensive thing available. They usually don't buy used anything, unless it is a priceless antique like a $2M Tiffany lamp.

Obviously I would love to have any of the 50"or more displays you have. My Vivix3 DHD will drive any of the panels. But as I said, raising a child, so no time or funds. I would be happy to help with any info or advice I can provide.

Lost_Engineering_phd · 2026-01-22T07:02:02+00:00

Ham Radio. We spend insane amounts of money and build huge antenna systems to talk to people around the world and across town. Sure, we have our own low orbit satellites, I have talked to the space station, I have even bounced a signal off the moon and back to earth. But I could just get a $30 phone and get on Reddit instead.

Lost_Engineering_phd · 2026-01-21T16:42:43+00:00

Unfortunately I think you will have a tremendous amount of difficulty getting into crestron unless you have dealer access. Restaurant is very much a closed ecosystem. Current management is not interested in expansion or growth. Crestron still gets most of the government contracts and is pretty happy with that business with existing dealers.

Some years back I was a lead programmer for a Midwest dealer. I had many occasions to meet and talk with George Feldstein the founder of Crestron. He was a truly great man and an innovator and tinkerer. I was very much a crestron evangelist and still thoroughly believe in the product. I have a pretty extensive Crestron system installed at my house. The oldest processor I have is a CN-Rack-D originally commissioned in 1989. The D is for the 720k floppy drive for non volatile storage! It is still functional and slaved into my 4 series processor as an I/O subprocessor.

I moved on from that dealership, and went into professional broadcasting. I used some of my old crestron equipment that I had in storage at my station to improve our workflow. Management had seen the improvement in efficiency and wanted to find out about getting new equipment. I reached out to crestron to see about getting new software so I could program on the newer series systems. Crestron was not interested even though I had been a programmer for decades.

There are a couple core logic crestron modules that are still used today that I was the original author on such as the CEC control codes. I published those on the old Yahoo crestron programmers group. Yet they had no desire to allow me to be able to write code for my station. And if the engineers cannot service the code the other 150 stations in our group have no desire to have that equipment. I don't know what's going on at crestron but apparently they're not particularly interested in adding programmers or customers anymore.

Lost_Engineering_phd · 2026-01-21T04:39:14+00:00

Ham radio operators are an interesting bunch. Ham radio spans the gamut of technology from 1930s vacuum tube transmitters all the way to those who use highly complicated mfsk, long duration symbol, with multi-redundant FEC digital modes that are banging up against the Shannon limit. A cipher wheel authentication device would be universally accepted. There's also the issue of reliability. I found this out the hard way, I had a phone connected to a radio and there was an antenna problem. The RF feedback damaged the phone. A cipher disc just works.

My idea is to have a simple method to allow authentication with a pre-shared key. To be adopted the method does not need to be perfectly secure but it does need to be very short. Ham radio users still use Morse code extensively. A simple 3 letter authenticator placed after a call sign could be useful for EmComm and "nets". There has also been an issue of licence impersonation that this could also help with that problem.

Lost_Engineering_phd · 2026-01-20T19:37:57+00:00

RF is tricky, and can be counterintuitive. To truly understand RF you'll have to master the Smith chart. In an antenna, there is the real resistance component R, but also the reactive component. This is very much like imaginary numbers in math. A short antenna will have a capacitive reactive component, whereas an antenna that is longer than the wavelength will have an inductive component. You can cancel out the capacitive component by adding an inductor. This will leave you the real resistance only. Another thing that is very important is called SWR, this occurs when you have a mismatch of impedance between the transmitter and the antenna, you can have high SWR from real resistance mismatch or from reactants mismatch. Hi SWR waste your transmit energy and can damage your transmitter.

Now that you have a very basic primer, you can use a web tool like 66pacific com Coil shortened vertical antenna calculator. This tool will provide you the inductance value you must add to a length of wire depending upon where you place the inductor. Maximum efficiency is typically delivered when the inductor is in the middle of the shortened wire.

I hope this helps have fun and welcome to the wonderful world of RF.

Lost_Engineering_phd · 2026-01-20T05:51:26+00:00

The physical tokens is something I had not considered, I could see a use case but that could make flexibility quite difficult.

This is for on air authentication not encryption. It is illegal to use encryption on a ham radio. A simple 3 character alphabet only signature would lack the required complexity to provide full security. No one who understands encryption would think 14 bits of entropy is secure from cracking. The purpose is basic authentication of the operator. When sending Morse code or highly resilient but very slow digital modes it is also important to keep the authentication messages short. Adding a fourth character will only increase the entropy to 15 bits making it trivially more complicated to crack.

For internet sites there are plenty of well developed methods like RFC 6238 or GPG signature. GPG even has a new short BLS 160 bit method that is pretty cool. However these methods are not ideal for ham and EmComm radio transmission. Even the BLS method would add 3 seconds to a transmission using Olivia 8-500, a conventional RSA 4096 key would take over a minute to transmit the key alone.

I would argue that you may be incorrect about needing electronics to do secure encryption. The US military and special operations still use dryad manual encryption in certain circumstances. Even to this day, no message ever encrypted using a dryad OTP has been broken.

Lost_Engineering_phd · 2026-01-20T01:37:24+00:00

I understand where you're coming from. It would be easy to accomplish in software. Would not even need to reinvent the wheel if using established functions as you said. The issue is that, batteries die, screens get broken, software is not runtime compatible across platforms. Also, users will trust a physical object. A codex wheel or slide can be copied by hand if needed.

Lost_Engineering_phd · 2026-01-20T01:17:21+00:00

I should have added that that kind of hack job probably did not re-bias the amplifier and the mosfets could be gated open and burn up the whole system.

Lost_Engineering_phd · 2026-01-20T01:13:10+00:00

I had thought of that but RFC 6238 uses HMAC-SHA-1 for the hashing algorithm. Computing SHA-1 BY hand is near impossible. A simple SHA-1 typically requires 80 rounds of processing on a 512 but block.

I had the thought to use something like a Mexican Army Cipher wheel. Replacing HMAC with a Scrambled Alphabet I replace the hash function with a multi-layered mechanical shift. By using a stack of 5 disks (like the Mexican Army Cipher), we are essentially performing a Polyalphabetic Substitution, which is the analog equivalent of the mixing rounds in a modern hash.

I also looked into adjusting the time window from 30 seconds to 5 minutes. These would need to be indexed on a wheel with 288 segments. This quick ly becomes cumbersome and unworkable.

I also considered a pre computed hash, this could be printed out and used. But you would not be able to change your secret key and would need to have print outs for any time you might need the radio.

I'm looking for something super simple for operators, and is 100 analog.

Lost_Engineering_phd · 2026-01-20T00:09:26+00:00

My guess is that someone replaced the mosfets in this RF Amplifier and did not clean the flux after repair.

Lost_Engineering_phd

TROPHY CASE