AutoDrive
From DDUtil
Contents |
Description
Given the fact that the Flex radios don't have any form of ALC (Automatic Level Control), which incidentally isn't all bad [1] according to many, then some other method is required to compensate for over-driving the amplifier. Also given the fact that the Flex radios are very accurate on the amount of power they produce with respect to the setting of the drive control why not just solve the problem with controlling the amount of drive going to the amplifier. Obviously using this method requires some form of software control to accomplish.
The DDUtil solution for this is to save the drive setting for each band and then reload them as needed when the bands change. To demonstrate, say it takes 44 watts of drive to produce 1000 watts of power from the amplifier on 20 meters and 50 watts of drive to produce the same output on 15 meters. DDUtil will set the correct level automatically for each band so the amplifier is neither over or under driven.
To go one step further DDUtil ties this function to the Operate/StandBy button (ctrl+O) on the Amps tab so when the amplifier is online the power setting is the correct amount for the amplifier (on that band) and when the amplifier is offline (barefoot) another set of values is used that has been predefined by the user. This gives the best of both worlds without having to manually set the drive level. The user can switch back and forth between the amplifier and barefoot operation and have the optimum power available for either situation.
This method has been tested extensively and has been found to be very reliable if the following setup procedures are followed.
Currently, only the HF bands 160 - 6 are setup for the Auto Drive feature since the VHF+ transverter form in PowerSDR has a similar feature already.
Setup
Open the Amps tab and locate the PTT and Auto Drive groups.
Controls
- Enable Auto Drive check box
- Selecting this check box enables the Auto Drive function which allows the automatic setting of the PowerSDR drive level from stored settings when bands change (see the Set Drive button below).
- Auto Drive Set button
- Pressing this orange button saves the PowerSDR drive level to the users settings file for each band.
- Operate/StandBy button (ctrl+O)
- This button toggles the PTT lines (via TX1-3) coming from the radio to take the amplifier on/off line.
Setting up Auto Drive for Amplifier Operation
- Tune the radio to the desired band and segment.
- Open the PSDR Antenna menu item (F5K only).
- Make sure the correct antenna and key line are selected.
- Make sure the amplifier and the PTT button are in Operate mode.
- Key the radio using either the CWX Key function or a straight key (or paddles with Break-In disabled) plugged into the CW key jack. Note: DO NOT use the Tune function or a microphone for this procedure, a constant key down is required.
- Adjust the PowerSDR drive to produce the desired amplifier output power.
- Press the Auto Drive Set button with either the radio keyed or unkeyed.
- Repeat these steps for each band.
Important Note: --------------- The Auto Drive function is directly locked to the PTT function and the Amp Bands group on the Setup tab. Make sure to check the bands you wish the amplifier to operate on or the PTT will not switch to Operate on those bands.
Setting up Auto Drive for Barefoot Operation
- Open the DDUtil Options menu and select Auto Drive.
- Enter the barefoot power value desired for each band.
Setting up Low Power Drive Feature
This feature lets the operator quickly select a lower output power from the amplifier if desired. Many times full amplifier output is not called for to maintain good communication quality when a lower power will suffice.
- Setup
- In the Auto Drive window set the Default Low Power Drive Level to produce the output power desired.
- Operation
- Switch the PTT to Operate (ctrl + O).
- PTT indicators should turn Green.
- Press ctrl + L.
- The PTT indicators should turn Brown.
- Observe PSDR drive level which should read what you set above.
- To turn off the Low Power Drive feature toggle the PTT indicator (ctrl+ O).
Auto Drive Expert Mode
The basic Auto Drive feature is designed to be most accurate with the mode where it was set. That proves to be inaccurate when switching from one mode to another depending on audio and processing settings employed if on a voice mode. To that end there is another set of controls to help the problem.
In the Auto Drive group four (4) additional controls are provided to enhance the Auto Drive feature.
When enabled the Expert mode will modify the original Auto Drive levels as defined by the AM, SSB and Digi values. These values should be entered as percentages of the baseline values entered using the Set button. It is mandatory to use the CW mode to set the baseline drive values as these values are used to derive the values for the other modes.
Follow these steps to setup the Auto Drive expert mode.
- In the Auto Drive group (Amps tab) enable Auto Drive and Expert check boxes.
- Use CW mode to set baseline drive settings for each band of interest. The other three modes (AM, SSB, Digi) will be calculated from this number.
- Note: Due to a CAT (Kenwood) deficit the other voice modes (SAM, DSB, FMN, DRM) are treated the same as SSB.
- To vary the drive based on AM, SSB and Digi mode insert a percentage (%) number in the appropriate text box.
- Use a positive number from 0-99 to indicate a % increase in drive from the CW setting.
- Use a minus (-) in front of a number from 0-99 to indicate a % reduction in drive from the CW setting.
- Selecting CW mode will show the baseline drive setting or alternately you can view the baseline settings from the main menu by selecting Options | Auto Drive | Amp Settings.
Example calculation: If it takes 60 watts to produce full output on CW and 45 watts to produce full output on SSB the calculation is 45/60 * 100 = 75% of the CW value or a 25% reduction. Enter -25 into the SSB window.
DDUtil will automatically apply the adjusted drive settings when ever the band or mode is changed.
Application Note: Due to the wide variance in operating conditions and amplifier characteristics there are no common settings that can be applied for everyone. This is strictly an individual station setting based on user preference.
Auto Drive Notes 1. Make sure the Auto Drive Enable check box is checked (Amps tab). 2. Make sure the Mode Change check box is un-checked (Setup tab) or that none of the Mode Change Macros contain any drive settings. 3. Make sure the proper Amp Bands are selected on the Setup tab.
References
- ↑ According to many notable experts such as Alpha Power and other amplifier manufactures, hardware ALC should be avoided in favor of Drive Level Control. Hardware ALC introduces distortion and non-linearity due to the fact that it can't act quickly enough since the envelope is already created before the ALC can take affect.
