Friday, February 6, 2015

A Collection of Mods for the DX-390 / ATS-818 Part 2.5

First I'd like to apologize for the delay in posting my light mod. I am the type of person who can't leave well enough alone :)

The radio is still in pieces on my bench and I asked myself if there were any other mods I'd like to do while I had it open.. Well of course! Another feature I added to the "nice to have" category is a way to remotely control the radio in some way. You see, I use this radio on camping trips with my kids as well as casual shortwave/HAM listening. Wouldn't it be cool to be able to change frequency, volume, etc with a remote control?

I remember the "new and improved" Bose Wave radio commercials which show new features such as a remote control, espresso maker, and pizza warmer. (Maybe I am exaggerating a bit on the espresso and pizza functions) So why not add this to my DX-390?

I have several remote controls laying around in junk drawers and think I have one that will work for this project. The next step is to incorporate an IR receiver circuit to interpret different functions of the IC and/or buttons. I plan to share my trials and errors with you along the way. (I better stop with the mods at this point before I add a WIFI interface to connected to HRD or perform an IF mod to for a spectrum scope, hi-hi)



Thursday, January 8, 2015

A collection of radio modifications for the Sangean ATS 818 aka Radio Shack DX-390 part 2 UPDATE

I will be digging out the schematic for my DX-390 and tinkering with the radio again. This time I will take pictures and share how to modify the backlight to work one of two ways..

1. Replace a component to extend the time from 15 seconds to whatever you like. Such as 15 minutes.. (I currently have this mod in my radio)


2. Add a latch circuit to control the function of the light switch to allow it to be on/off with a press of the button. I am in the process of researching this functionality using a 555 timer or transistors. Please comment if you have any simple circuits requiring only a few components capable of operating on 6 volts.

I may also add information on how to replace the stock, incandescent lamp with a LED while the radio is on my bench. Stay tuned!


Jesse, W9JES

iPhone and Ham Radio - A Realization

I wrote this editorial in 2010 as a response to the great debate over the Echolink smartphone apps..  Figured I would publish it here now to see what your perspective is on this technology 5 years later. Feel free to comment.

Ham radio has many facets which makes it an enjoyable hobby. Homebrew and experimentation are two of them. How does the iPhone fit into this? It is not a ham radio, although it uses RF. I see the iPhone as a neat piece of technology that has apps for everything. That's great, but what about ham radio apps? There were over two dozen apps that I saw for ham radio and one of the newer apps is Echolink. This allows people to talk to each other on the Echolink network through their phone over a wifi network. I've recently talked to people on Echolink who were using the iPhone and the audio quality is great. I guess Apple put good mics in the phones.

After the brief wave of astonishment escaped my face, I started thinking about the good, bad, and ugly of using a smartphone for amateur radio. Back in the good old days of ham radio there was a device called an auto-patch. The auto-patch was used for making land line phone calls via a handheld or mobile radio, typically through a repeater. The repeater passed DTMF tones to the auto-patch, then to the telco. Audio was transferred using half duplex and it worked fine as long as the connection to the repeater did not drop. This was a really cool way of talking to friends and family as long as you didn't care who listened in. Before cellphones became popular, this was an elite technology to have. Did that just sound like the opposite of the iPhone Echolink app? It sure was!

I guess my point is RF links to land line connections existed for decades. We've just figured out a way to re-purpose them, right?

Now I don't think the autopatch hurt the hobby because it was heard by anyone on the frequency. This limited the amount of time spent on the "phone" as well as controlling the types of conversation. Is the iPhone good or bad for ham radio? Here is my observation..

Smartphones are evolving into handheld computers.

This is true and we have no way of knowing how far it will go. I have an Android smartphone which has a web browser, email, texting, music player, GPS, games, productivity apps, a full keyboard, wifi, and more. How much more can they cram into these devices? Those of you who use Echolink know it has to be connected to one of the designated servers using a computer with Windows or Linux. If your smartphone has a WiFi connection, how is it any different from a laptop or desktop pc?

The Bottom Line

Is Echolink still ham radio? I think so. It is a form of ham radio utilizing new technology. On the other hand, I believe that a ham radio operator should also continue to utilize our allocated RF space as well. Especially while it is still available to us. I'd hate to see the bands re-provisioned for non-amateur use.


Jesse, W9JES