Transmitter Page
I have have had a number of transmitters over the years. Currently there is a Viking Valiant, Elmac AF-68 and my Collins 20V-3 Broadcast Transmitter.
EF Johnson - Valiant
This Valiant is in great condition. It has all of the audio mods as gleened from the internet and ER Magazine. Just do a internet search on Valiant mods and you should get all the information you need. Right now I have got station audio chain fed in thru the phone patch input on the rear. A 600:600 modem isolation transformer, a dc blocking capacitor and you're on your way. It sounds great. I use it on 160 meters most often.
Multi Elmac - AF-68
This is the almightly Elmac AF-68 transmitter. Although it is not as famous as its earlier brother, the AF-67, it is an outstanding performer and the looks are a welcome improvement. It uses a pair of 5880's to modulate a single 6146 to give a very effective high level plate modulated signal. Many compare the audio and signal quality to the Johnson Ranger. The VFO is more stable that the Rangers and doesn't suffer from the dreaded "resistor overheating problem". It DOES require an external power supply. Band coverage is 80-6 meters. The one small annoyance is that it requires the use of a 22.5 vdc bias battery which mounts underneath the chassis. Most folks will take out the battery and utilize a couple of 22 volt zener diodes to get the same effect or build a small voltage doubler from a 12 v source. The output power can be lowered enough to drive a high powered amplifier just fine.
BEWARE: When buying one of these or the AF-67, make sure you check the continuity of the interstage audio transformer. A well documented weakness is that this transformer becomes open. A new one can be had from Antique Radio Sales for about $25.
Tidbit: Multi Elmac made the electronics for all Stanley wireless garage doors openers back in the 60's. I know, I've got several.
Eico 720 transmitter & 730 modulator
Here is my Eico 720 Transmitter and matching 730 modulator. Eico (Electronic Instrument Company) is best known as a maker of test equipment kits as well as audio equipment kits. They entered the amateur arena with a few smaller transmitters but really took a design leap and made this transmitter resemble one of their stereo receivers than an amateur transmitter. The transmitters can be found quite readily but the modulators are a whole different story. This pair is in my shop and don't get much airtime, unfortunately.
Select: Special Collins 20V-3 Page
Utah UAT-1
No, you aren't looking at a diabolical machine from Dr. Frankenstein's laboratory. The size is roughly 24"x36"x8".
This is a transmitter kit that was put out by the Utah Radio Company of Chicago in the mid 1930's. Most of us only know the name Utah as a manufacturer of speakers. Utah Radio put out a set of kits in 1937, much like Thordarson and others, that allowed an amateur to purchase an a la carte station. They referred to this as their "Add a Unit" series. The ham of that era could start with just the 80 watt cw exciter and add kits till he had a 500 watt AM Phone transmitter.
For instance, kit #1 was the 80 watt exciter. Kit #2 was a speech amp/modulator for that exciter. Kit #3 was an antenna coupler. (See pic above which features the antenna coupler #3 attached to the exciter #1.) Kit #4 was a 500 watt power amp and kit #5 was the modulator for it.
I'm very fortunate to have come across this beautiful specimen as seen above. For a much deeper analysis of this rare transmitter, please follow the attached link to Henry Rogers' wonderful look into the UAT-1 transmitter at his Radio Museum. www.radioblvd.com/1937Station.html
Henry has done such a marvelous job of chronicling his adventure with the UAT-1 there's no point in me doing it. While you are at his museum, look at the other featured examples of old time radio.
The UAT-1 will be teamed with the NC-100X, which is featured on my Receiver Page.
Listen to 1st Utah to Utah in 30 years. K7RLD and W7YBS (listen)