[AMRadio] AM Radio

[W2XJ]

On 1/25/12 4:56 PM, Kevin Raper wrote:
> 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.
>
I said well maintained. There are few that have not been butchered over 
the decades. Also, there are few if any AM stations still running a tube 
TX in the 21st century that would be spending hard earned money on HD, 
especially at the 1 KW level. Any station running tubes these days would 
be doing so because they can not afford to go SS and have been in that 
state for a few decades. Stations that can afford to go HD and choose to 
do so are probably on at least their third SS TX. The stations around 
here replaced MW 50s with and 317s with DX 50s 16 years ago then 
replaced those with 3DX50s and Now Nautel NX.
>> 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.
CCA went bankrupt in 2002. The last time I was in the GA factory they 
were only doing FM.

I know of no high power AM tube rigs (50 KW and under) still actually 
being manufactured. There are a few listed on websites but not actually 
built. Solid state AM TXs have been built to 2 megawatts for a while 
now. Of course there are shortwave tube TXs at 100kw and up.

>> 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.
Power pebble was an unofficial nickname the name was still power rock. A 
314R1 is one of the newer units since 314 is the Continental designation.

>
>> 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.

Actually I installed one in 1965