AmateurRadio.com

Back in September I attempted to repair a Kenwood/Trio TR9500 UHF All-modes transceiver for a fellow club member. It had a faulty microphone pre-amp which I replaced and all seemed well but it had further issues with the receiver. Cutting his losses and wanting shot the owner sold it to me for the princely sum of £10.

I have had her back on the bench and initially couldn't find anything wrong. However in real use it become apparent that she was in fact profoundly deaf! Picking up test transmissions from the nearby FT857D or Baofeng outputting into a dummy load was one thing but it wasn't receiving anything else!

From the service manual and schematic I deduced that it could be the initial RF receive amplifier. It is a dual-gate mosfet (3SK76) It proved tricky but I managed to source a replacement on eBay and it was a simple job to replace once I'd extricated the PCB.

I can report it is now working and the video below shows it monitoring the GB3EE repeater in Chesterfield. From the coverage map I shouldn't be able to hear it but I can and reception has been marginal at best using other receivers but it repaired TR9500 doesn't have any problems.


I wonder if the rig has been subjected to a high RF field in the past this could easily have damaged the receiver amplifier and an induced RF into the microphone lead could have damaged the microphone pre-amp. It just seemed strange it having both faults.

Tuesday night is the last 432MHz UKAC contest and hope to use her in anger.
Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

My Christmas present arrived last night. Being a patient and practical person, I waited until this morning to open it and as you can see, it’s the 2014 SKCC Club Key from LNR Precision. Click the image for a better look.

I had wanted to get this one in this calendar year as I’m not sure how much longer it will be available. I had picked up the Pro Pump NT9K Standard Version key while at Dayton this year and have been very pleased with its smooth action. This smaller version is just as well-built and enjoyable to use as the “Pro”.

I know that because the new key already has ten contacts to its credit…

Tagged: keys, skcc

Jeff Davis, KE9V, is a regular contributor to AmateurRadio.com and writes from Indiana, USA.

 

Greetings, salutations and happy holidays! Today your weary hosts (minus one) bring you some great information about great topics, like: Why you should avoid qrznow.com, why you should upgrade your WordPress installation, why you should try ElementaryOS, why the government is like a turtle, and why bacon renders your argument invalid. Be well, listen often, and stay safe.

73 de The LHS Guys

Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

A co-worker of mine got his GMail hacked. I doubt anyone guessed the password — it was not easily “guessable.” There was probably some malware running on a machine he used to log in at some point. Who knows?

Why is a hacked GMail or Yahoo Mail account a big deal? Because once they get into your e-mail account, they have access to EVERYTHING.

Think about it… if someone has access to your e-mail account, they can launch any number of frauds against you. They can read through your email and see that you’re on vacation in Hawaii. Then, when you’re asleep, they can email your contacts asking them to send money via PayPal using credible details about your travel (“I twisted my ankle on the beach — please send cash!”). They can also reset the passwords on your bank accounts, Facebook, etc. Access to your e-mail account is, to a hacker, like a kid in a candy store.

For a number of years I’ve been using Two-Factor Authentication on my GMail account. Each time I log in, you can set it up to send you a text with an additional code that’s only valid for a short period of time. Alternatively, they make an app (called Google Authenticator) that gives you the code even if you aren’t in wireless range. Using two-factor authentication makes it MUCH harder for someone (other than you) to access your GMail account.

If you don’t always (or ever?) carry around a smartphone and would rather have a physical device, you can use an “electronic key” that you plug into your computer. I’ve used a Yubico security key (the cheap one — there are more expensive versions) and can recommend it. It’s a little device that hooks to your keychain. It almost looks like a USB thumb drive, and while it does get inserted in a USB port, it is much more rugged that a standard thumb drive. You can set it up so that the key has to be plugged into your computer in order to log in to your account.

I found the security key to be easy to carry around, it’s cheap ($18 on Amazon – not an affiliate link), and waterproof. The key can be used to provide an extra layer of security not only for GMail, but also WordPress (via 3rd party plugin), Lastpass, and more. One downside, however, is that it only works with the Google Chrome browser at the moment. I would imagine as more browsers adopt the FIDO U2F standard specification, more options will be available.

Whether you choose to use one of the two free options, or pony up for a physical device like the security key, the only thing that matters is that you do SOMETHING. If you use GMail, watch the video above to learn step-by-step how to do it. Please do it now and avoid waking up some morning to find that you’ve been hacked. It’s not a good feeling.

Matt Thomas, W1MST, is the managing editor of AmateurRadio.com. Contact him at [email protected].

One of the great things about amateur radio is the number of different ways in which the hobby can be enjoyed.

For over a year now my health has been poor because a brain bleed in September 2013. Before then, I enjoyed QRP QSOs (mainly SSB), construction and field experiments from VLF to optical. Since my stroke I have been clumsy and (until recently) not allowed to drive. Very very slowly, normality is returning but I think it will be way into 2015 before I can call myself well.

In the meantime, I still manage WSPR and other digital modes from home. I can even, albeit briefly, manage our local 2m FM net and the occasional VHF/UHF contest. Some people enjoy satellites, MS or moonbounce. Others just like to ragchew on 80m.

We must rejoice that there are so many different, yet equally valid, ways of enjoying ourselves. We have a great hobby.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Being involved in VLF amateur radio is a very specialised activity requiring special (but low cost) kit to be successful. Casual listening is highly unlikely to be successful. Long distance reception of amateur VLF signals usually involves looking for signals using Spectrum Laboratory software locked to a VLF MSK signal so that very narrow bandwidths can be looked at for hours or days on end.

Most amateur VLF tests are done on 8.27kHz as this is unallocated spectrum in many countries.

News about amateur VLF activity can be found at https://sites.google.com/site/sub9khz/ . There has been very little amateur VLF work done this year but amateur VLF signals have crossed the Atlantic.

Tests using utilities assisted earth-mode do not involve big loading coils. Just under 6km has been achieved with just 5W using this mode, before I had my stroke! The kit was simple too. See https://sites.google.com/site/sub9khz/earthmode .

One of the things I am really looking forward to, when fit again, is some more field work with VLF using earth-mode.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.