The Station At AA8V
Sections 5 and 6

Click on any item in the photo for information on that item, or look in the list below.

Sections 5 and 6 Push-To-Talk Relay System Hallicrafters SX-96 Receiver Ameritron AL-572 Amplifier Astatic D-104 Microphone Wingfoot 813 Amplifier Johnson Viking Ranger Coaxial Antenna Relay

Click on any item in the photo for information on that item, or look in the list below.

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The AA8V Station
Sections 5 and 6
 Section 5 (Left Side of Photo)  Section 6 (Right Side of Photo)
 Sections 5 and 6 Introduction  AA8V Wingfoot 813 Linear Amplifier
 Coaxial Antenna Relay  Astatic D-104 Microphone
 Johnson Viking Ranger AM Transmitter  Ameritron AL-572 Linear Amplifier
 PTT Relay System  
 Hallicrafters SX-96 Receiver  

Introduction:
Section 5 (Left Side of Photo):
Section 5, on the right in the photo, contains a complete 1955 vintage AM station consisting of a restored Johnson Viking Ranger AM transmitter and a restored Hallicrafters SX-96 receiver, along with their associated accessories: a push-to-talk (PTT) relay system and an antenna changeover relay.

Section 6 (Right Side of Photo):
Section 6 of the station features a pair of high powered amplifiers. At top is the Wingfoot 813 Amplifier, and at bottom is the Ameritron AL-572. The Wingfoot 813 Amplifier is a homebrew amplifier for the 80m, 40, 30m, and 20m bands with an output of 250W. The Ameritron AL-572 is a commercial amplifier with an output of 1000W on CW and 1300W PEP on SSB.

The AA8V Station
Sections 5 and 6

 
Coaxial Antenna Relay:
A coaxial antenna relay is used with the Johnson Viking Ranger and Hallicrafters SX-96 receiver as part of a push-to-talk (PTT) system. When the PTT on the microphone is pressed, the PTT system activates the antenna relay, switching the antenna from the receiver to the transmitter.

The relay can also be used in CW mode with the automatic T/R system. In this mode, the 6x2 receiver or the Jupiter receiver can be used with either the Johnson Ranger transmitter or the 6AG7/6146B transmitter system for fully automatic transmit/receive switching.

 
Coaxial Antenna Relay


 
Johnson Viking Ranger AM Transmitter:
In the middle and late 50s thee most coveted transmitter for any ham running AM was the Johnson Viking Ranger. It was the transmitter to have if you were running AM. With the ability to run on 160m - 10m, it featured a built in VFO and high level plate modulation with a powerful, great sounding modulator. With a handsome front panel and the ability to meter five different circuits the Viking Ranger set the standard for AM operation. The Ranger wasn't cheap. In 1955, a factory assembled Ranger cost $293, the equivalent of over $2500 in 2015!

This particular Ranger was factory assembled, and it is fully restored. However, even after restoration the internal VFO is not as stable as I would like. Rather than use the internal VFO, I use my digital VFO and feed the VFO signal in through the crystal socket. The digital VFO works beautifully with the Ranger, and gives me absolute stability and digital frequency readout.

 
Johnson Viking Ranger


 
PTT Relay System:
When running AM, I prefer to use a push-to-talk (PTT) relay system. Rather than modify the Ranger, I simply feed the PTT line from the microphone to this external PTT relay system. On the back panel the relay system has a 120V AC outlet that is normally off, along with a normally closed RCA jack and a normally open 1/4" keying jack.

A coaxial antenna relay is plugged into the 120V outlet, the receiver mute circuit is connected to the normally closed RCA jack, and the transmitter key is connected to the 1/4" key jack.

When the PTT switch on the microphone is closed, the system turns on the 120V outlet activating the antenna relay, opens the normally closed RCA jack, muting the receiver, and closes the key jack, keying the transmitter.

 
Push To Talk Relay System


 
Hallicrafters SX-96 Receiver:
The Hallicrafters SX-96 was just about the finest receiver available from Hallicrafters in 1955. Only one other receiver from Hallicrafters was better than the SX-96, and that receiver cost more than twice as much as the SX-96. As it was, the SX-96 cost $249 in 1955, the equivalent of over $2000 in 2015.

The SX-96 is a double conversion selectable sideband receiver. It is general coverage receiver, covering the AM broadcast band up to 30MHz. It has five different selectivities: 5kHz, 3kHz, 2kHz, 1kHz, and 0.5kHz. The 0.5kHz selectivity is outstanding for a receiver built in 1955 and is very good for CW. The 2kHz and 3kHz selectivities are perfect for SSB. However, it is the 5kHz selectivity, coupled with an effective noise blanker, that makes this receiver so desirable: it is perfect for AM . Good fidelity on AM requires a wide receiver bandwidth, and many modern receivers cannot accommodate such a wide bandwidth. The SX-96 sounds great on AM, and when it is combined with the Johnson Viking Ranger is makes for a great sounding vintage AM station.

This particular SX-96 is completely restored. All electrolytic capacitors have been replaced along with some of the capacitors in the 50kHz IF strip. It has been realigned, and works as well as when it was new. It is particularly good for AM broadcast band DXing, short wave listening, and AM operation in the ham bands.

 
Hallicrafters SX-96 Receiver


 
AA8V Wingfoot 813 Amplifier:
The Wingfoot 813 amplifier is a grounded grid linear amplifier that uses an 813 in class AB2. The amplifier can operate on the 80m, 40m, 30m, and 20m bands and has an output of 250W when driven by the Wingfoot VFO exciter. The amplifier has a relay to bypass the amplifier and cut off the tube during receive periods. The relay can be activated by the knob on the front panel or remotely by a signal from the Wingfoot VFO exciter. The amplifier uses simple convection cooling to cool the tube. No fan is used. The power supply is a remote unit that sits on the floor under the amplifier RF deck.

 
Wingfoot 813 Amplifier


 
Astatic D-104 Microphone:
The Astatic D-104 microphone is one of the most popular microphones ever marketed. In the 1950s it was particularly popular since it mated very well with the AM transmitters of the day, such as the Johnson Viking Ranger. The microphone has a bar on the side that is used for push-to-talk (PTT) operation. When properly wired to a PTT relay system, the operator need only press the bar to place the entire system in transmit mode.

 
Astatic D-104 Microphone


 
Ameritron AL-572 Linear Amplifier:
The Ameritron AL-572 is a near-legal limit amplifier, which means that it has a maximum output of 1300W PEP, which is only 0.6dB less than the legal maximum of 1500W PEP. A difference of 0.6dB is not audible on the air, yet the amplifier costs less than half of some legal limit amplifiers.

The AL-572 uses four 572B triodes in parallel. These tubes are economical and are now being manufactured to higher standards than in the past. In actual use on CW I can get about 1150W out of the amplifier on 160m, though I always keep it cut back to the rated output of 1000W. I am impressed by how cool the amplifier runs even at 1kW output. This is due to the Instantaneous RF Bias which shuts the amplifier off between dots and dashes. This particular AL-572 also has the QSK-5 option installed, so I can run QSK (instantaneous CW break-in) even when running high power. I also have no relay noise or clatter when using the amplifier. The switchover from receive to transmit is completely silent. An extra LED on the front panel, to the left of the XMT LED, serves as a QSK indicator and lights whenever the QSK-5 circuit is activated.

I regularly use the amplifier on 160m where noise is a big problem and using an amplifier is often the difference between making a QSO and not making a QSO. My AL-572 is configured to run on 240V AC, and I recommend using 240V to power any large amplifier if at all possible.

 
Ameritron AL-572 Linear Amplifier



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