Monday, November 5, 2012

My Atlas 210x Arrived!

On Saturday morning, November 3rd,  FedEx delivered my recently purchased Atlas 210x that I won on eBay the previous week.  I wasn't really expecting it to come on Saturday, but much to my surprise, it was sitting outside my side door.

Excitedly, I ran outside, grabbed the box, and rushed into my kitchen to open up the container with my toy.

When I brought it out and unwrapped it, I was floor at the size of the radio.  It is much smaller than other radios of the era, but large in comparison with today's mini marvels.

So, down into the shack, quickly connected power to both positive leads and the ground, connected my Hustler 4BTV, and hit the switch. signals.

A quick surf over to the Atlas page led me to the problem.  There is a 9-pin socket on the rear apron of Atlas rigs...and certain pins must be jumpered for NORMAL operation.  When I did this, the rig JUMPED to life.  I heard signals that were buried in-between signals.  And I was pleasantly surprised to learn that the tuning drum was spot-on accurate.

Testing the transmit was my next step.

Flipped the switch to "CW" and pressed down upon my Nye-Viking straight key.



Was it the finals?  I posted a message on the Yahoo Atlas 210/215 forum, and many believed that it may have been the driver transistor...and ARCHAIC RCA 40582 unit.  A quick snip of the 2 leads, and an MRF476 was soldered gently into place.

After another try...still no TX.

So, as it stands, the 210 is a project.  Since I own the manual to the radio, I have the component voltage chart.  My next step is to test the voltages, test resistor continuity, and replace what I hope to find that went bad.  Overall, it's a 37-year old rig...and I EXPECTED there to be issues with it.

But the RX...the receiver is so stable!  It is MUCH more stable than I ever dreamed it could be.  I've had older radios before with drum/dial tuning...and one drifted worse than the next.  Doing RTTY or any digital with my old Ten-Tec Argonaut 505 always led to ops on the other end telling me that I was drifting.

Yes, I KNOW I'm drifty!

But, I noticed right away that the Atlas' RX was rock solid.  To further prove that point, I connected the audio to the LINE IN of my Windows 7 PC, and started MultiPSK.  Then I tuned to 14.076 MHz...the 20m JT65a hangout.  And much to my amazement, the old Atlas could copy the exotic weak signal mode with NO issues.  In fact, every mode I fed into the PC was faithfully demodulated without any noticeable drift.  Not bad at all.

So, this radio will need some TLC to get it back into shape, but since the components are not the typical surface mount and proprietary IC/CPUs of today, restoration SHOULD be fairly simple.  It's just FINDING the component(s) that failed in the transmit chain.

More to come, I'm sure.