A site of endless curiosity

Archive for May 11th, 2009

Servicing Superheterodynes

leave a comment »

We have a real classic fom the History of Radio. In the 1930’s to mid 1940’s Rider published a book called “Servicing Superheterodynes”.  You can find a real hardcopy on ebay.  We have a PDF version.

At the time the first edition of “Servicing Superheterodynes” was published the superheterdynereceiver was first becoming generally known to the public.  As the years passed, so did the tuned radio frequency set pass out of popular favor to be replaced by the well liked and today, well behaved, superhet.  Today, everything is the superheterodyne… The few t-r-f receivers, which are still being produced, are completely overwhelmed by the number of receivers based on the heterodyneprinciples. And – if you please, these receivers are becoming more and more complicated daily.

– John Rider from the 1934 edition

Servicing Superheterodynes

And please, don’t forget this modern book by Richard McWhorter.

The Vacuum Tube Shortwave Radio: Understanding and Troubleshooting.

The PDF of the book is password protected.
The password is “allamericanfiveradio”

Written by frrl

May 11, 2009 at 4:21 am

CCrane CCRadio with 2 Meter Ham Band

leave a comment »

Holy cow. What hath God wrought?  Someone has put 2-meter ham reception in a commercial AM/FM radio.  Check out the new C.Crane CCRadio-2 that has AM/FM/Weather/2-Meter Ham Band.

Previous versions of the CCRadio had AM/FM/Weather/TV-Audio.  In the age of digital television, the ability to receive analog TV audio is useless.  So, what do they pick as a replacement.  Wow – the 2-Meter Ham Radio Band.  Perhaps placing 2-meter ham band reception on the table top consumer radio may spur interest in Amateur Radio by ordinary citizens.

Here is what C.Crane  has to say about its new radio.

The radio designed for long-range AM Reception and now Emergencies!

The new CCRadio-2 has the same familiar look and layout as previous models of the CCRadio but with even better AM Reception and the addition of the 2-Meter Ham Band. The boost in AM performance comes from our patented Twin-Coil Ferrite(r) AM Antenna, and other improvements built into the CCRadio-2. AM stations continue to sound just right, thanks to audio that’s optimized for voice clarity. After you select a station, the CCRadio-2 evaluates the signal for several seconds and then locks in for the highest signal possible.

FM reception is a little better than the CCRadioplus while the Weather Band can keep you informed of any government-issued alerts. The addition of the 2-Meter Ham band may make the CCRadio-2 a life saver during an emergency like hurricane Katrina. 2-Meter Ham operators are early on the scene and they donate their time while handling perhaps 90% of the emergency coordination efforts. The CCRadio-2 can act like a simple radio scanner and search the five memories for ham operator communications. The sensitivity (squelch) can be adjusted for best results. More information about the 2-Meter Ham Band can be found at\2-meter.

The CCRadio-2 comes in our original Black Mica or a new Titanium color. It features a brighter, clearer LCD display with a full backlight and three levels of adjustable brightness plus an “off ” setting. Five years ago we made changes to the durability of our CCRadio LCD display that have proven to be robust. Other features include: 5 memories per band (AM, FM, Weather and 2-Meter bands), adjustable display light, adjustable bass and treble, clock alarm, sleep timer, auto scan, stereo headphone jack, line-input jack, and line-output jack.

Weight: 4 lbs (without optional batteries) Size: 11″ W x 6.5″ H x 4″ D.

Written by frrl

May 11, 2009 at 4:10 am

Posted in Uncategorized

Tagged with

Dayton Hamvention 2009

leave a comment »

Did you miss the 2009 Dayton Hamvention?  Too bad.  Take a video tour

Go to the Dayton Hamvention 2009 virtually compliments of WA5KUB

The Illiad and the Odyssey Dayton Hamvention style

When Paris of Troy stole Helen (the most beautiful of all women) from the king of Sparta a great epic story began to unfold.  It’s too bad the greek writers and historians like Homer did not have a video camera, global wireless network, and the internet.  If Homer had this then high school students would not be tortured reading the Illiad and the Odyssey – they could just watch highlights on YouTube.

But WA5KUB does have a video camera, a global network, and the internet.  So you will be able to watch the great epic journey to the Dayton Hamvention 2009 and the events that will transpire.  Perhaps he will not find Helen – the most beautiful of all women – but maybe he will find some good hamfest buys in the fleamarket.  I once saw a kitchen sink at a hamfest – how about a big wooden horse?

Modern technology to the rescue

How do we do it?

We are using windows media encoder 9 on a laptop with a camera. The camera is mounted under the mirror in the front windshield.  From time to time we will rotate it around to give a view inside the car.  We will also be using a cam mounted on a helmet (called the helmet cam). You can see a picture of it on this page.

The laptop has a wireless network card.  We are using Verizon’s national broadband access. We have added an external 6db antenna outside the car and have also inserted a 2 watt amplifier. The freq is CDMA around 1850-1900 Mhz.  In broadband areas like Dayton and Memphis, you can get 180K bursts upload and about 700K download speeds.  On the road outside the broadband cities, we will have slower speeds like 50k upload and 100k download.

While traveling between cities, the connection speed may drop low and we may be transmitting video as low as 30Kbps but it is possible to transmit in some areas much higher (100Kbps)  The signal strength will determine what speed and quality we transmit at.  Since the laptop is going to have limited bandwidth, we send that video stream back to a Media Server.  This server is connected to the internet with a very high capacity uplink.  When you access the web page, you will be watching video directly from our media server.  If we are able to get a 100K stream connection from the laptop to the server, then all of you will be able to watch video at the 100K rate.

You can see the importance of the server now.  Say if we have 300 viewers on at the same time, each would be using 100K of uplink bandwidth.  so 300x100K = the need for a 30 Mbit uplink connection to the internet.   Hopefully while in Dayton at hamvention, we will have high speed connection and can up the video speed to 100k or better.

Check out these links for all the details

Written by frrl

May 11, 2009 at 4:08 am

Posted in Uncategorized

Tagged with

%d bloggers like this: