Raspberry Pi3B and Ensemble Intallation

Shown above is an entire SDR ham station complete with the SoftRock 40/30/20M Ensemble Transceiver, Raspberry Pi3B, StarTech 7.1 USB Sound Card ( I & Q Processing) , 5 VDC 3 amp Power Supply for the RPi3, Sabrent USB Sound Card for the Mic/Headset, A microminiature wifi, Keyboard and Mouse plus a 7 Inch HDMI Display. We need only add a 12 VDC power supply for the Ensemble and connect an Antenna and we can be doing FT8. Pretty Cool.

Just a short note about power supplies and antennas. Recently I gave a friend some of the same pieces as above so he could assemble his own SDR station. His kit included the SoftRock V6.2, Startech 7.1 and an old Rsapberry Pi2 that was in the junk box. He was so delighted to get this on the air. Then he reported that the unit no longer worked. That seemed strange as he simply turned it on and nothing!

Well after about a week, he sent me an email that he was back on the air. The problem was his "cheapo" 12 VDC power supply. There are several things that are a must in any ham shack: 1) a linear good quality 12 VDC Supply and 2) a resonant properly deisgned and properly erected antenna. A chunk of wire dangling outside a window does not meet the antenna requirements!

We will now look at the individual pieces of our SDR ham station...

Here we have the Ensemble SDR Board available from Five Dash. The ports include the USB interconnect to the RPi3, a jack for a set of Paddles, Line Out, Line In, 12VDC Power Input and finally the Antenna. I will publish a Modification so that you can "key" a huge RF Power Amp. Who works QRP these days? If you go to wb5rvz.org there is excellent documentation on the Ensemble RxTx. There are some embedded links on that site that further explain SDR, how it is generated and how it is decoded.
Shown above is our Raspberry Pi3B with the plastic case cover removed. Note the heat sink on the top of the Broadcom Processor. That is not enough as extended operation in a hot garage (my shack) will make a Red Thermometer appear on your screen. You can find these small 12 VDC fans at many suppliers. The RPi's don't need a lot of CFM but what you do need to do is remove the heat from the case. My install is to find a circular template about the size of the fan circular shroud and draw that area on the case top. Using an exacto knife I cut out the circular area. Keep the size tight as you want to have enough case top remain to drill the 4 mounting holes. With care you can have a professional looking job and not something done by a shoemaker. [That is an inside Italian joke -- Who gave you that haircut? It looks like it was done by a shoemaker!] Very Important -- use a 5VDC 3 amp supply. One of the problems that plague a RPi3 is that if the supply is undrerated like 1.5 or 2 amps --the voltage sags and you get erratic operation.

In the photo above we have two sound cards. The StarTech 7.1 has three connections. One (not shown) is the USB connection to the Raspberry Pi3B and that is on the back side opposite the two cables that are on the front side. You will need two 1 foot long cables with a 3.5MM stereo plugs at each end. I labled one cable Line Input. That cable plugs into the 2nd jack on the front panel labeled LINE IN. The second cable plugs into the jack labeled SPEAKER (this is Line Out) right next to the LINE IN. The other ends of these two cables connect to two 3.5 MM panel jacks mounted on Ensemble Circuit Board. IMPORTANT: Connect the Line In on the USB to the Line In on the Ensemble. That also applies to Line Out (speaker on the StarTech) to Line Out on the Ensemble. Several years ago I loaned one of my SDR Rigs to a ham -- got the usual phone call --your rig doesn't work. He thought that Line In had to connect to Line Out. In's with the In's and Out's with the Out's.

The smaller device is also a sound card made by Sabrent and is used exclusively for the Headphone (or powered speaker) and the Microphone. Because the 4 USB ports on the RPi3B are close spaced -- this device didn't fit well with the other USB plugs. Simple solution: I have a 2 foot long USB-A to USB-B extension cord and I simply plug in the cable and then plug the Sabrent into the cable. I also have a Logitech Headphone/Mic headset and built into the USB plug end is a similar sound card. BUT if you want to connect your setup to a set of powered speakers then the Sabrent gives you that flexibility.

Here we have a 7" HDMI Display made especially for the Raspberry Pi. This may be considred a luxury; but sure keeps things neat and tidy. Some may find the screen size too small; but makes for less clutter in the shack. Now in addition to the HDMI connector you will need to have a separate 5 VDC supply for the backlighting. This also can be used as a touch screen but I have not attempted to invoke that capability. Perhpas a compromise here would be to get the larger 10.1 inch screen made for the RPi as that would be a notch up. Keep in mind any HDMI capable monitor/display will work. I have an old 19" LED TV that has HDMI --works perfect with this rig!

One thing I have found is that I usually set the screen size resolution on a much larger HDMI where you can pack in a lot of Pixels. I then switch to the 7" and that setting holds. You need this higher pixel setting to see the whole control panel. If you connect the 7" HDMI without doing this interim step, then the default settings on the display are much larger and you can only see one half of the control panel. That is unsatisfactory for normal usage.

This wireless Keyboard with Mouse Pad will work with the SDR Station and is a quick and dirty way to have some fun. It will work perfect for FT8. As you only need to click on a station and boom the RPi3 takes over and has all of the fun making a QSO. But for general web surfing and making any adjustments on the control panel, a guy like me with fat fingers and only types with two fingers then not so good. Logitech makes a wireless keyboard and separate mouse combo that would be ideal. Typical operation is with a mouse making selections so the wireless mouse is prefect. The reason I mention the Logitech --it only takes up one USB port!

A Typical Wiring Table for the SDR

Ensemble XCVR

USB Connector to Raspberry Pi3

Paddles if into CW

Line Out to Line Out on the StarTech 7.1

Lline In to Line In on the StarTech 7.1

12 VDC Power Input (Barrel Connector)

Antenna ~ BNC Connector

Raspberry Pi3

5 VDC 3 Amp Power Supply Input

HDMI Connector

USB 1 ~ Wireless KeyBoard and Mouse

USB 2 ~ StarTech 7.1 Sound Card

USB 3 ~ Enssemble Transceiver

USB 4 ~ Sabrent (or Logitech) Sound Card

StarTech 7.1 Sound Card

USB ~ To USB 2 on eth RPi3

Line In ~ To Line In on the Ensemble XCVR

Line Out (Speaker) ~ To Line Out Ensemble XCVR


HDMI to the Raspberry Pi3

5 VDC Power Input (Separate Supply)

Wireless KeyBoard and Mouse
Wireless Dongle on USB 1, Raspberry Pi3
12 VDC Power Supply
Connected to the Ensemble Transceiver via a barrel connector
Connected to the Ensemble Transceiver ~ BNC

1 foot long cables with 3.5 MM Stereo plug at each end

2 Foot long HDMI Cable

1 foot long USB cable (StarTceh to Rpi3)

2 foot long USB A to USB B ~ Sabrent

Power Cable ~ Ensemble to 12 VDC, 2' length