Amateur Radio Weekly – Issue 108

Repeater owner bans Baofeng radios
Simply put, these radios do not allow for “advancing skills in both the communication and technical phases of the art” (Part 97.1).
N4NJJ

Online streaming platform for DMR Brandmeister network
All Brandmeister Talk Groups are streamed on-demand and active participants will show up on the dashboard automatically.
Hoseline

Ladyada passes Extra exam
Ladyada took all 3 exams at once, including perfect scores.
Adafruit

Fo Time podcast is now HamRadio360
In an effort to keep it Fun, we decided to do the 50th episode with a Live Video Stream. You’ll quickly see why we do the show with audio only!
HamRadio360.com

Iridium Antenna Hack
Here’s several channels simultaneously visible in Inspectrum.
ShareBrained Technology

Hearing The Hum?
Glen set up a website where people could report what they were hearing and found that it was a worldwide phenomenon.
amateurradio.com

Learning CW is not a sprint
I am in the 9th month of my CW / Morse Code journey and I will readily admit that in my case it has been slow, steady progress rather than a sprint.
Ham Radio QRP

ESDR: New portable SDR HF transceiver
The ESDR features a large color display, digimode decoder/keyer, 2x USB ports and micro-SD card. The required supply voltage is 12.6V and the maximum output power is 30W.
QRP Blog

Differences between UV5R / UV82 series Baofengs
The UV5R, RA, RB, RC, E5, F8, GT3, etc. are all cousins.
Miklor

A lightwave adventure
VE7CNF successfully inaugurated his lightwave station earlier this week, on Monday night, completing a nice two-way CW contact between West Vancouver and Mayne Island.
VE7SL

Rare and classic shortwave QSL cards
A couple months ago at my local ham radio club meeting (the NCDXCC), my buddy Paul Greaves (W4FC) mentioned that his passion for amateur radio DXing originated with shortwave broadcaster DXing.
The SWLing Post

Video

FCC enforcement team
We got a great demonstration on how the FCC enforcement team keeps unlicensed & wireless spectrum violators at bay.
YouTube

FS 5000 receiver demo: Cold War spy radio
This is a demonstration of the receiver section of the FS-5000 cold-war shortwave spy radio, developed during the eighties by the government branch of AEG Telefunken.
YouTube

Amateur Radio Weekly is curated by Cale Mooth K4HCK. Sign up free to receive ham radio's most relevant news, projects, technology and events by e-mail each week at http://www.hamweekly.com.

4 Responses to “Amateur Radio Weekly – Issue 108”

  • Bill Taylor KC5DPJ:

    Reading the comments about the banning of certain radios from a repeater reminded me of my very first contacts with some hams that happened to own an Amateur Radio store a block from my home. At the time I was involved in (gasp) CB. I had been told by the man that gave me a cb radio that I needed a linear in order to “get out”. So I walk into the radio store and looked at all the treasures. I mean those guys had all kinds of hardware in bins. They also sold new Amateur radios. I was looking around in amazement when one asked if they could help me. I told him I was looking for a linear. He asked me my callsign so since I had a FCC license for CB ( this was in the very early 70’s. The guy recognized it as a CB callsign. He told me I wasn’t entitled to a linear and they didn’t need nor want my business.
    Now zoom ahead to the early 80’s. My best friend and later my Elmer talked to me for a couple of years about Amateur Radio. I was very polite to him but let him know that it would be a cold day before I ever associated with a group like that. Over the years he persisted and finally loaned me an ICOM 02AT to listen to. He made it perfectly clear that I was not to key the radio. Just change the frequencies and listen. Well it sounded a lot better than CB plus by that time I had given up CB because of the language. I was trying to raise three children.
    I ended up getting a No Code Tech license in 1993. I’m now a General class and plan on upgrading to Extra. I found out that most hams weren’t like the first I met. They could have explained things a little different and maybe told me the benefits of Amateur Radio and what I could legally do and the different ways to communicate.
    My first mobile FM radio was the brand that was sold in the store and it was the only store in the area for Amateur Radio. Needless to say I purchased my radio out of state and my first Repeater Call book I purchased out of state.
    There are a lot of us that can’t always afford or willing to spend the money when we have more important family obligations.
    Had it not been for the friendship we shared and the persistence of my Elmer I would have continued to think all amateur radio operators were like the guys in the store and I never would have met the wonderful people that share my enjoyment of the Amateur Radio Service.

    I believe there are a lot of people that either can’t or won’t spend the bigger bucks for a rig for a hobby they might not even stay with. The less expensive rigs give a person the chance to get involved in Amateur Radio and in time they will upgrade their rigs and even their licenses so they can be more involved. 73.

  • David WB4ONA:

    As to banning certain radios…

    (Note I would post this on the N4NJJ site, but he’s got it locked down on a subscription basis.)

    N4NJJ says (regarding inexpensive Chinese radios), “…these radios are not capable of pre-emphasis or de-emphasis…”, then N4JJ goes on to say that he’s been a ham for over a decade and until recently he didn’t know about emphasis. Finally, he goes on to declare that the claimed lack of emphasis in the Chinese radios is in large-part the reason why he is going to ban all users of these radios from his repeater.

    Well, here’s what I have to say about that…

    Without proper testing and presentation of the evidence, I think N4JJ is wrong to publicly claim a particular brand of radio does not employ industry standard emphasis, then use that unsubstantiated claim as basis in large-part to ban a whole class of operators using said radios from his repeater system.

    I don’t own any of these cheap Chinese radios, nor do I have a schematic (yeah, as if you could trust the schematic).

    But I do know this…

    1. Emphasis (pre-emphasis in the Tx and de-emphasis in the Rx) is not a simple thing to test, especially in the receiver. You have to break the Tx-Rx link and look at the transmitter and receiver separately. You will need a spectral plot of the audio chain, ideally in real time. You will also need clean, stable audio and RF frequency-variable sources with some means of level adjustment and impedance matching.

    When testing the receiver it is very important to inject a clean in-band carrier that brings the radio out of open-squelch and into the operating region, but far from full-quieting. Keep in-mind the AGC loop is working against you during this process. It is only at this operating point that you can properly observe the de-emphasis response in operation, and take data.

    2. Since we’re talking about analog NBFM radios here, the pre-emphasis and de-emphasis would likely follow (at a minimum) the TIA/EIA-603 standard. This would require including a simple RC high-pass then RC low-pass filter. The total additional cost to the radio is negligible, as is the cost of designing the filter in. To not include even the simplest implementation of emphasis in the Chinese radios is quite unlikely, especially because of the problems it would cause with reduced link performance and distorted audio when used with industry-standard equipment. Note: In-practice, emphasis does employ a slightly more complex filter than the bare minimum required, this is to help suppress sub-audible tones. But again, the realization employs only passive RC components and is very simple and cheap to include.

    3. Assuming you have a reliable and up to date schematic for the radio, simply looking at the circuit often will not reveal precisely where the emphasis takes place. In other words, if you’re looking for a simple RC filter, and don’t find it sticking out like a sore thumb where it should be on the schematic, don’t assume there is no emphasis included! Skilled analog engineers are masters at tailoring frequency response without adding components, or adding components where you would least expect. I can’t go into this subject in-depth here but just to give you a taste: If you need to add (e.g.) an nth-order high-pass slope to a stage, before adding new components you would first look to employ existing interstage input/output characteristics such as coupling components, impedance, gain distribution (which changes coupling capacitance through Miller effect), etc. So if you think something is missing and/or out of place on the schematic just by looking at it – don’t.

    4. Today, it is possible that emphasis is built-in to the radio’s integrated circuit. This is especially the case with modern radio-on-chip components which internally implement the radio as a direct conversion quadrature detector and accompanying on-die DSP. These highly integrated solutions are typically more difficult to test than analog designs, and referring to the schematic (assuming it is correct) will not help you to identify how the emphasis is employed.

  • Goody K3NG:

    There’s so much wrong with the Baofeng article, I’m not sure where to start. The author only recently learned about emphasis and de-emphasis, but owns repeaters (yes, plural). Really? I sure wouldn’t admit in public I have repeaters and just learned about emphasis and de-emphasis. That’s rather basic. I can forgive someone with a “cheapie radio” (his words) not knowing about this, but not a repeater owner. Furthermore, he says emphasis affects the volume. That’s not quite right, and some of the on air problems he’s supposedly experiencing could just be modulation issues and have nothing to do with preemphasis.

    He notes the Baofeng has a lousy front end and “will start squawking every time the operator passes by a credit card machine or clothes drier.” What bearing does this have operating on his repeater system?

    He claims at the end of the article his “reasons are purely technical, and not a form of elitism”, yet he devotes a whole paragraph to the “type of operator” Baofengs attract. How is that technical?

    “Simply put, these radios do not allow for “advancing skills in both the communication and technical phases of the art” (Part 97.1).” Really? How does one advance the radio art with a YaeKenwoocom rig on a repeater, over?

    This passage takes the cake: “Think of all the licensed hams lost to the Baofeng….he/she runs into an operator on the air that refuses to talk to him because they clearly must be stupid for choosing a Baofeng.” Perhaps he means people like the author who is alienating these people?

  • jeff n1kdo:

    The anti-Baofeng guy is just being a real tool.

    He claims that the Baofeng radios don’t have proper FM emphasis and de-emphasis — they do, it’s in the specs, the normal 6dB/octave pre-emphasis. He cannot explain the what and why FM transceivers have pre-emphasis and de-emphasis. I hear Baofengs all the time on my 2m system, and they sound fine, once the lids^h^h^h^h new hams turn off their roger beeps.

    It’s especially silly to be acting all elitist when he’s not even running what “real repeater elitists” would call a “real repeater” — he’s got some antique Motorola junker made out of mobile radio parts (a GR-1225) on a Diamond antenna with some cheap foil-shielded feedline. Maybe this is why some radios sound like crap on his system.

    The guy is acting the fool, saying he’s not an elitist while running an unpublished tone and required MDC tones for access to his toy repeater.

    Bah.

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