Trials and Errors #64: The New Hams -- Shot Across the Bow for ICOM, Yaesu and Others!

Agree. I've transmitted the most esoteric waveforms of any ham with a real SDR (an Ettus B210) on frequencies as high as 10 GHz, But when I want to do "traditional" ham radio, I use my ICOM IC-7300.

 

My experience with long waiting list for products is in high power RF amps and antennas, mostly items that these new maker style of software/IT hams have limited knowledge about.

While I see the Maker side as good we also need a balance between Antenna design, software design and RF analog design to succeed and with only the Software It/maker guys getting the all of the spotlight we are still going to fail.

Having worked designing The RF side of avionics transmitters for my first 21 years then spending a couple of years designing the first LDMOS RF power amplifiers for the cellular division of Motorola then getting bored and moving back over to avionics transmitter design for the past 15 years I recently became bored again with RF transmitter/power amp design and started to dabble in the software side of SDR radio mainly for an understanding to help me working with the Software engineers that I deal with.

What I see by many of these new IT style of maker hams and which I also experience in the commercial avionics field with our professional software engineers is that most of the software engineers in both fields, maker ham and professional, have a limited knowledge if any on the transmitter side and zero on the antenna side.

If you look at the too many to list SDR designs online you will notice that while many are very nice and at the beginning appealing, they all start with a nice software designed receiver and a stand alone no PC required interface that handles numerous modulations formats along with some very nice stand alone features such as spectral scopes, digital receive decoding etc.

However; the majority of them end up having a simple on/off keyed transmitter at the start and when the time comes to add in a transmitter the results are a spurious disaster with the transmitters having more Birdies than an Audubon society meeting.

I saw the same thing in the professional avionics field where we always have a shortage of dedicate RF designers, most times it is so bad that we typically have a ratio of a couple of hundred software engineers to one or two RF guys with the end result being so bad that a Software engineer will attempt to finish a high power transmitter design with the end result being a temper tantrum in meetings where the software engineer then makes a comment about a lack of understanding of RF saying that it's witchcraft and Black Magic and other such nonsense.

Now don't get me started on the lack of understanding on antennas as I'll leave all antenna comments to Chip but suffice to say I work with some professional/commercial software aviation radio designers who are managers of our company and none of them have any idea that the antenna is the most important part of all transceiver designs.

 

Not questioning all the other points you made, but what does the antenna have to do with transceiver design, other than (ham radio-wise) preferably presenting a 50 ohm load to the radio? Maybe I missed something?

 

It has a lot in fact,

The antenna is as much as the transceiver design as is the power supply that will be used , the coaxial feedline and the connectors used so why would any product designer ignore any of these items?

Who would design a product without first thinking about what it will be working into, in particular the type of antenna that works with your transceiver.

An example in several instances I designed aviation transmitters and in every design the antenna was the last item considered by management and frequently ignored which resulted in customer complaints and regulatory notices.

I don't know of any antenna that covers the range of frequencies I want to use without needing to resort to an antenna tuner and antenna tuners are items that in my field we cannot use due to weight limitations and such and i expect the same from my ham radio equipment.

As a result one Company I worked with in the UK actually designed my company a 118 to 400 MHz COM radio antenna, which while it was larger than the typical thin AM com antenna, it consisted of Pin switched radiator elements to produce good performance across the desired operating range.

In aviation radios as in every other transceiver the effects of a poor antenna need to be considered at the beginning of the design as opposed to the last thing, the antenna effects the transmitters ruggedness design and it also effects the receiver performance.

We see this is many ham transmitters marketed by ham manufacturers where a unsuspecting ham transmits into his/her mediocre antenna and the final stages fail.

In my field since management always fails to consider the effects of the typical cheap low cost VHF style of bent whip antenna used in avionics I have to design the transmitter to take an open or shorted antenna without failing and this is something that the ham transceiver manufacturers fail to consider.

This also applies to the receiver end, a poor antenna effects receiver coverage range and in my field this results in customer complaints and more so nasty Notices from the FAA about pilots not hearing ATC reliably, so why shouldn't the antenna and any detrimental effects be considered in ham radio designs?

 

I understand what you're trying to convey. But still, installers of commercial and military radios should be professionally trained to know what kind, coverage, and quality specs the antenna to be used is required for a particular radio. Any radio and its design is only capable and effective, RX/TX-wise, depending on the antenna attached to it, no matter who the end user is that just hits a PTT button. Far be it for me to question your extensive expertise though, so I'm sure your comments are valid.

As far as ham radio usage is concerned, if someone burns up the PA due to an improper antenna installation, I'd just chalk that up to ignorance. They should read the radio and antenna manuals. Built-in antenna tuners only have so much range...usually maximum 3:1 SWR. But that's why they're 'amateurs'.

 

Hey, Dave. You could have given me a little credit for teaching that class at DEFCON! This was the fourth year in a row that I've been able to teach a class there. I have also taught classes at other "cons" around the country, thanks to a grant from ARDC.

Also you should give a shout out to Ham Radio Village, for administering exams there. Over the years, I'd guess that they've licensed more than a thousand new hams, at DEFCON and other cons.

 

And on an aircraft, the aerodynamicists have a significant say in what antennas must be like physically, and their locations on the airframe.