[AMRadio] AM Radio

[Kevin Raper]

On Jan 25, 2012, at 2:17 PM, W2XJ wrote:

> There are very few well maintained pull out tube BC rigs.

There are more than you may think. The advent of HD-Radio is forcing more stations to replace otherwise good Transmitters.

> New TXs have been solid state for 30 years.

CCA Made the AM1000D until 2003. FM and High Power AMs with Tube Finals are still being made, and I do know of one Broadcast FM rig converted to 2 Meters.

> Most of what I hear of what people are 
> converting are rigs from the 50s and 60s. There is a webpage detailing 
> the conversion of a 1KW Power Rock PDM TX which is 70s vintage

The 315R1 "Power Rock" is a 5KW Transmitter. It's Baby Brother, the 314R1 "Power Pebble" was the 1 KW model and was made well into the 1980s. One of the stations I worked for bought a new Power Rock in 1989.

> and I 
> think one Vanguard which was a Linear with a 4CX3000 final and a solid 
> state diode modulated exciter (early  60s vintage).

The Vanguard and Vanguard II were made in 1969 and 1970.

> Many of those TXs have been mistreated over the years and can easily not 
> match the original schematics. So, yes many may be considered junk 
> depending upon one's skill in renovating.

Many transmitter were butchered, but most can be restored. RCA Transmitters are also noted for the Wiring getting Brittle and shorting out causing Fires, so it is a good Idea to make a completely new Wiring harness for RCA Transmitters. The BTA-1S and the BTA-1Ms are especially noted for this, but I went ahead and Re-Wired my BTA-1R1, and I noticed the OEM Wiring was getting Tired.

73,
Kevin Raper
KJ4HYD
CE WCKI WQIZ WLTQ

There is no limitation to the fidelity of AM radio. From a mathematical standpoint, AM does better in frequency response than FM. - Leonard Kahn