Introduction to configuring PowerSDR and UCB for Weak Signal...
Introduction to configuring PowerSDR and UCB for Weak Signal Microwave Applications
| System Dependencies |
| Minimum PowerSDR Version: |
1.6.0 |
| Applicable Hardware: |
SDR-1000
|
Content provided by: Mike, KMØT
Using the SDR-1000 with PowerSDR for microwave applications can be approached a number of ways. Initially one needs to integrate a 28 to 144 MHz transverter into the overall system. This can be either with the DEMI 144-28FRS transverter internally mounted within the SDR-1000 enclosure, or any other 144 MHz transverter that would be externally connected.
Why the 144 MHz transverter you say? Well, most of the “high band” transverters, 902 MHz and up are typically driven by 144 MHz. Transverters for 50, 144, 222 and 432 MHz are typically driven by 28 MHz. So for microwave applications on 902 MHz and up, one needs this intermediate step to go from 28 to 144 MHz.
Then there are few ways to interface the transverter chain. One can simply connect the SDR-1000 to the 144 MHz transverter, and then connect the 144 MHz transverter for example to a 10 GHz transverter. When you set the power levels for each transverter and connect the PTT (Push-To-Talk) lines properly, when you transmit at 28.100 MHz on the SDR-1000, you get 10,368.100 MHz output from the 10 GHz transverter.
If you have more than one microwave transverter, then one can use a RF relay to control the RF line from the 144 MHz transverter to switch between the inputs to the microwave transverters. You just need a way to switch the relay and also route the PTT line to the selected transverter. This is fairly simple for a few microwave transverters, but as one adds more microwave bands, the switching, relays and PTT routing become a bit more cumbersome and your still looking at the 28 MHz band readout on the SDR-1000.
Lots of folks have come up with ingenious ways to do all this effectively, but with the UCB – (Universal Control Board) and the integrated PowerSDR software controls, the ultimate microwave interface is possible. A single click of a band button can control which microwave transverter is selected, route the RF and PTT lines, and show the actual frequency of operation. It’s a microwave operators dream come true!
There are many ways to interface to the UCB – as it’s a “universal” system. The RF relay(s) chosen from surplus sources primarily dictate how one will make the connections for control and RF. Below are screen shots from the UCB interface used at ARS KM0T. The selection of an 8 pole single throw relay dictated the overall setup. This relay was used to switch the 144 MHz RF line to the different microwave transverters. The software interface built into PowerSDR control the PCB (Printed Circuit Board) relays on the UCB, which in turn control the position of the 8 pole RF surplus relay. The UCB PCB relays also route the PTT line to the appropriate transverter for transmit control. The UCB is connected to the SDR-1000 back panel X2 connector via a typical VGA cable. There is a “pass-through” connection on the UCB to input an external PTT signal and access to the other pins on the X2 connector.
 Diagram 1
Above is a diagram of the UCB and how it interfaces with the SDR-1000 and 144 MHz transverter. The 144 MHz RF signal is passed through the 8 pole relay to feed the microwave transverters. PCB relays on the UCB control the position of the surplus RF relay and route the PTT line.
 Screen Shot 1
Above is a screen shot of PowerSDR showing a beacon signal source right on the 10 GHz calling frequency of 10,368.100 MHz. Note that the “10G” VHF+ band button is selected. The labels on the band buttons are user programmable. It could say “10”, “10GHz” or some other label with a 5 character limit. “10G” just seemed to fit well with the current size of the button. The label characters are programmed in the “Button Text” section of the “XVTR Setup” menu shown in a below screen shot.
 Screen Shot 2
Above is a screen shot of PowerSDR showing a beacon signal source right on the 24 GHz calling frequency of 24,192.000 MHz.
Again, note that the “24G” VHF+ band button is selected. Note that “AVG” is selected. Averaging of the signals shown on the 20 KHz bandscope (Panadapter) help locate small blips of signals visually. The averaging time in milliseconds is user settable within the main PowerSDR setup menus. One can adjust the averaging time to get what works best to accommodate any users personal preference.
 Screen Shot 3
This screen shot shows PowerSDR on the entire desktop, with the “UCB Configuration” and “XVRT Setup” menus. These menus along with PowerSDR are viewable at the same time if your screen real estate is large enough. This particular screen shot is shown on a Dell 20” wide aspect LCD monitor. However, once all the settings are completed and saved in both the UCB and XVRT setup menus, these can be closed while using PowerSDR.
 Screen Shot 4
The above screen shot shows the “UCB Configuration and Setup” menu. This menu interfaces the hardware aspects of the UCB to the PowerSDR software. Note the 16 x 16 matrix of check boxes. This represents the UCB’s 16 address PIC chip memory and the 16 on board UCB PCB relays. What this means is that one has 16 different ways to control the 16 UCB PCB relays.
When a particular address is selected, let’s say for example address zero as shown in the screen shot, relay 16 is active and all the rest are off. Note that each PCB relay on the UCB has two sets of NC and NO contacts. These NC and NO contacts give lots of flexibility whether the relay is in an on or off state.
 Photograph 1
Above is a photograph of the UCB, RF relay and interconnection wiring.
So once you set the check boxes to your needs, then one can “Write” one address line or “Write All”. This in turn will send the data to the UCB PIC chip to be stored. If you make a mistake, one can redo the check boxes on a particular address line, then just click the “Write” button for that address. That way one does not have to rewrite the entire matrix.
Once the check boxes are programmed, then one clicks the “Enable Relays” button to activate the PIC chip matrix. At this point, one could use the mouse to select the pick button address lines on the left side and see the UCB switching the relays as it relates to the programmed matrix. But that’s no fun, so that’s why the “XVTR Menu” was developed to tie it all together.
 Screen Shot 5
The “XVRT Setup” menu interfaces the PowerSDR front panel band button controls with the appropriate UCB address. It also allows one to program frequency bands to show the proper frequency display when the correct “LO offset” is entered.
So as an example for “Band Button” 5, when button 5 is selected on the PowerSDR console, its associated with “UCB Address” 5
to control the UCB PCB Relays programmed for that address. However, the “Button Text” for “Band Button” 5 is 5760, so that’s what shows up in “Band Button” position 5 on the PowerSDR console.
Then one sets the proper “LO Offset” for button 5 - 5732 MHz. (5760 – 28 = 5732) Then the “Begin” and “End” frequencies are set, typical 2 MHz wide. It is these beginning and ending frequencies which allow the PowerSDR software to display the proper frequency.
If you were to look back at the “UCB Configuration and Setup” menu, one would see that for UCB address 5, UCB relays 3 and 13 are checked. For this particular setup, UCB relay 3 when active selects the 144 MHz RF line to be routed to the 5760 MHz transverter. UCB relay 13 when active routes the PTT line to it as well.
However, everyone’s setup would vary, as the surplus RF relays would determine how the check boxes for control are set up. For ARS KM0T, the UCB PCB relays 1, 2 and 3 control the position of the 8 pole RF relay which route the 144 MHz RF to the appropriate microwave transverter. UCB PCB relays 9 through 15 control the PTT line routing. UCB PCB relays 4 and 5 control some feedline switching. Addresses 8 through 15 were not needed, so check boxes for the unused UCB PCB relays 6, 7 and 8 were selected as a diagnostic indicator.
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Last Modified:Sunday, August 03, 2008
Last Modified By: Administrator
Type: HOWTO
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