Frequently Asked Questions
Here are a few questions that seem to pop up often and the answers to them. If you have a question that is not covered here, please email me at the link below. I will gladly answer your question as soon as I can. Thanks!
Q. Do you use a K7DYY transmitter?
A. Of course I do!
Q. Why don't you just make a three band transmitter?
A. There are technical issues with the wider frequency coverage that it would require. I have not found a way to overcome those limitations ... yet!
A. There are technical issues with the wider frequency coverage that it would require. I have not found a way to overcome those limitations ... yet!
Q. I see that the SuperSenior has a VFO? How does it work?
A. There is a rotary dial on the front of the SS that allows you to step up or step down in frequency in 1 khz steps. The frequency is displayed in the LCD display. When the desired frequency appears in the display, you are good to go! The VFO is a Si570 design. The software has been tweaked to allow faster tuning when making large frequency excursions or changing bands.
A. There is a rotary dial on the front of the SS that allows you to step up or step down in frequency in 1 khz steps. The frequency is displayed in the LCD display. When the desired frequency appears in the display, you are good to go! The VFO is a Si570 design. The software has been tweaked to allow faster tuning when making large frequency excursions or changing bands.
Q. Where is the bandswitch?
A. The band switches automatically to match the frequency that you select. I tried to make it easy!
A. The band switches automatically to match the frequency that you select. I tried to make it easy!
Q. My D104 processor adds hum/noise/RF and it wasn't there before. Why?
A. The audio processor is by necessity a very high gain device. If you have noise or hum present in your particular setup, it may be a problem with the audio processor installation. The processor should be enclosed in a shielded place, with the shortest practical leads from the microphone cartridge and careful attention to grounding. This is why I recommend installing it in the base of the D104 where all of these conditions are easily met.
A. The audio processor is by necessity a very high gain device. If you have noise or hum present in your particular setup, it may be a problem with the audio processor installation. The processor should be enclosed in a shielded place, with the shortest practical leads from the microphone cartridge and careful attention to grounding. This is why I recommend installing it in the base of the D104 where all of these conditions are easily met.
Q. I am using an old "boatanchor" receiver. How does the muting work?
A. The SuperSenior can be configured to mute any receiver. A form C relay contact set is available on the 8 pin Aux connector at the rear of the transmitter. The common may be wired to give you normally closed contacts for use in many of the older tube receivers, such as a 75A2 or HQ-170 or SX-100, and by wiring your receiver mute to another pin, you can mute modern receivers that require a closure to ground. It is very versatile and those contacts can be used for many other things too!
A. The SuperSenior can be configured to mute any receiver. A form C relay contact set is available on the 8 pin Aux connector at the rear of the transmitter. The common may be wired to give you normally closed contacts for use in many of the older tube receivers, such as a 75A2 or HQ-170 or SX-100, and by wiring your receiver mute to another pin, you can mute modern receivers that require a closure to ground. It is very versatile and those contacts can be used for many other things too!
Q. Why does it have three fans if it doesn't produce much heat?
A. Actually it runs very cool and the three fans gently pull air across the internal heat sinks to keep it that way. Those fans are the same type of fans that keep your computer cool!
A. Actually it runs very cool and the three fans gently pull air across the internal heat sinks to keep it that way. Those fans are the same type of fans that keep your computer cool!
Q. What about the SWR protection.
A. Well it's pretty easy. The SuperSenior provides latch off SWR protection that is reset by cycling power. The display will indicate "HIGH SWR" telling you that you have entered the protection mode. The SuperSenior protects itself from most of the "oopses" that occur in a ham shack.
For instance, OVERMOD protection has also been added. The SuperSenior will limit peak power with moderate over modulation, however I have added overmodulation shutdown that will protect the transmitter against damage from extreme overmodulation. This extreme overmodulation would occur as a result of ground lead failure on the audio input or high levels of RF feedback. It is also reset by cycling the SuperSenior power switch.
Q. Does the built in protection cover all faults?
A. Although the SWR shutdown circuitry does a reliable job of protecting the transmitter with common faults such as no antenna or wrong antenna connected, the transmitter can be vulnerable to damage due to arcing in coax, connectors or antenna tuner.
The symptoms pointing to arcing are good match at carrier but SWR shutdown on audio peaks.
The protection circuitry cannot always shutdown fast enough with arcing and the final FET's may be damaged.
A. Well it's pretty easy. The SuperSenior provides latch off SWR protection that is reset by cycling power. The display will indicate "HIGH SWR" telling you that you have entered the protection mode. The SuperSenior protects itself from most of the "oopses" that occur in a ham shack.
For instance, OVERMOD protection has also been added. The SuperSenior will limit peak power with moderate over modulation, however I have added overmodulation shutdown that will protect the transmitter against damage from extreme overmodulation. This extreme overmodulation would occur as a result of ground lead failure on the audio input or high levels of RF feedback. It is also reset by cycling the SuperSenior power switch.
Q. Does the built in protection cover all faults?
A. Although the SWR shutdown circuitry does a reliable job of protecting the transmitter with common faults such as no antenna or wrong antenna connected, the transmitter can be vulnerable to damage due to arcing in coax, connectors or antenna tuner.
The symptoms pointing to arcing are good match at carrier but SWR shutdown on audio peaks.
The protection circuitry cannot always shutdown fast enough with arcing and the final FET's may be damaged.
Q. How do I adjust my percentage of modulation? I don't see a control for that.
A. Modulation is controlled by the amount of audio that you feed the SuperSenior. If you install the K7DYY audio processor board in the base of your D-104, the output control on the base of the microphone provides a convenient way to adjust your audio level. If you use outboard audio equipment, an output control is usually provided. Also, a peak limiter is designed into the Senior to keep you from exceeding 100% modulation.
A. Modulation is controlled by the amount of audio that you feed the SuperSenior. If you install the K7DYY audio processor board in the base of your D-104, the output control on the base of the microphone provides a convenient way to adjust your audio level. If you use outboard audio equipment, an output control is usually provided. Also, a peak limiter is designed into the Senior to keep you from exceeding 100% modulation.
Q. How soon will you ship my order?
A. Please check with me for availability.
A. Please check with me for availability.
Q. My antenna system uses a tuner to make everything happy. Can I cut the power back some way to safely tune the tuner?
A. Yes, of course! The front panel has a switch labeled Spot and the other is Transmit. If you turn both of these switches on at the same time, the SuperSenior will put out about 70 watts for this purpose. You should not try to modulate the SuperSenior with the switches in this position as it is meant only for tuning.
A. Yes, of course! The front panel has a switch labeled Spot and the other is Transmit. If you turn both of these switches on at the same time, the SuperSenior will put out about 70 watts for this purpose. You should not try to modulate the SuperSenior with the switches in this position as it is meant only for tuning.
By the way, using a tuner with the SuperSenior is a very good idea. Although the transmitter will safely protect itself from high SWR, the protection circuits will sense that something is not right and you may experience some undesireable effects, such as audio distortion.
Q. Can I use my audio equipment that I normally use?
A. If you are referring to normal audio processing equipment and regular dynamic or condenser or ribbon microphones, the answer is probably yes. As long as your equipment meets the SuperSenior's input requirements and most equipment does. The SuperSenior audio input requires line level (0 dbm) 600 ohm unbalanced audio for 100% modulation. Most of the time you would want to isolate the balanced output of your equipment with a transformer but that's just good practice anyway.
A. If you are referring to normal audio processing equipment and regular dynamic or condenser or ribbon microphones, the answer is probably yes. As long as your equipment meets the SuperSenior's input requirements and most equipment does. The SuperSenior audio input requires line level (0 dbm) 600 ohm unbalanced audio for 100% modulation. Most of the time you would want to isolate the balanced output of your equipment with a transformer but that's just good practice anyway.
Q. How do you switch from receive to transmit? Does it have PTT?
A. T/R switching is built into the SuperSenior. A relay switches the antenna from your receiver and also provides muting contacts to mute your receiving equipment. Jacks are located on the rear panel. A PTT connection is provided in the microphone plug on the front panel as well as a toggle switch that will also switch your equipment into transmit, should you not have a microphone with PTT.
A. T/R switching is built into the SuperSenior. A relay switches the antenna from your receiver and also provides muting contacts to mute your receiving equipment. Jacks are located on the rear panel. A PTT connection is provided in the microphone plug on the front panel as well as a toggle switch that will also switch your equipment into transmit, should you not have a microphone with PTT.
Q. What kind of AC power does the SuperSenior transmitter need?
A. It uses regular 120 VAC. It does not require 240 VAC as do most high powered transmitters in this class. It will draw approximately 5 amps, slightly more on audio peaks, when transmitting. Remember Class D is extremely efficient and if you are looking to heat the shack, like most high power AM transmitters would, forget it. Put on your Long Johns, your parka and gloves and slide up next to a DYY SuperSenior this winter!
A. It uses regular 120 VAC. It does not require 240 VAC as do most high powered transmitters in this class. It will draw approximately 5 amps, slightly more on audio peaks, when transmitting. Remember Class D is extremely efficient and if you are looking to heat the shack, like most high power AM transmitters would, forget it. Put on your Long Johns, your parka and gloves and slide up next to a DYY SuperSenior this winter!
Q. Why not put the microphone preamplifier inside the SuperSenior?
A. That's a good question! Being that there is a lot of high power (square wave) circuitry in that little box, the environment is not a good place to house low level circuitry like a microphone preamp. Not only that, some of the most popular ham microphones, like the venerable D-104, is best served with as short a lead as possible between the element and the first audio stage, as in the K7DYY Audio Processor mounted in the D-104 base. That means that the coiled cord now carries line level audio, nearly immune to RF and noise!
A. That's a good question! Being that there is a lot of high power (square wave) circuitry in that little box, the environment is not a good place to house low level circuitry like a microphone preamp. Not only that, some of the most popular ham microphones, like the venerable D-104, is best served with as short a lead as possible between the element and the first audio stage, as in the K7DYY Audio Processor mounted in the D-104 base. That means that the coiled cord now carries line level audio, nearly immune to RF and noise!