LD-1B SDR
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The LD-1B improves on the LD-1A with three additional preselector filters for better low-frequency performance, a front-panel power switch and power indicator LED, and a mute indicator LED. It also has an internal antenna relay, and “hooks” for installation of a 5-Watt transmitter module which is targeted for availability by the end of the year. Installation of the transmitter will not require any cutting, drilling or soldering, and it will not alter the appearance of the LD-1B.Like all Lazy Dog products, the LD-1B was designed and is manufactured by Lazy Dog Engineering LLC, right here in the Garage Shoppe. Like its predecessor, the LD-1B’s design was heavily influenced by KB9YIG’s excellent “Softrock-40″ series of simple SDRs. After building a crystal-controlled Softrock for 20 meters, I was very impressed by its performance. While I didn’t (and still don’t) have the equipment to make exhaustive performance measurements, it seemed just as good as my FT-817 at a fraction of the cost. The only problem was its frequency coverage. I could receive anything within 48 kHz above or below the fixed LO frequency of 14.060 MHz. I set out to create a general coverage version, covering 500 kHz – 30 MHz, with plans for an add-in transmitter module. | ||
 View of Rear Panel |
The result is the LD-1A, which is similar in concept to the Softrock 40 version 5. Instead of a crystal oscillator and phase shift network, the LO comprises a pair of Analog Devices AD9834 DDS chips which, which are always set to the same frequency but with a 90-degree phase shift between them. The single third-order preselector filter in the Softrock was replaced by five electronically-switched third-order filters in the LD-1A (eight in the LD-1B) extending low-frequency coverage to 500 kHz (100 kHz for the LD-1B). A Silicon Laboratories microcontroller selects the preselector filter and controls the DDS chips, as well as providing a USB port so the whole thing can be controlled from a PC.We listened to the comments of our customers, and adapted the design of the LD-1B to the way our SDR’s are used in the real world. The LD-1B has all connectors on the rear panel, with the front panel reserved for the power switch and indicator LED’s. In other words, you can set it on the desk with all the cables out of sight, just as you would do with a “conventional” radio. | ||
 The PCB slides into slots in the enclosure. |
The PCB slides into slots in the sides of the enclosure. The connectors, indicator LEDs and power switch are mounted directly on the PCB, with NO wires to come loose or become intermittent! The PCB is exactly the length of the enclosure, so to disassemble it you just remove the screws from one or both panels, remove the panel(s), and slide the PCB out. | ||
 LD-1B PCB |
The LD-1B also has a place on the PCB for easy addition of an Analog Devices ADUM 4160 USB isolator when it becomes available early next year. |
You can order an LD-1B from Lazy Dog Engineering
I haven’t been able to put together detailed performance measurements, but here are the specifications I can provide:
| FrequencyCoverage: | 100 kHz – 30 MHz | ||
| Sensitivity: | Comparable to Amateur-grade receivers | ||
| Image rejection : | Comparable to Amateur-grade receivers | ||
| Overload Characteristics: | Comparable to Amateur-grade receivers | ||
| Power Supply: | 6 – 14 VDC “wall-wart” with 2.1 mm x 5.5 mm male connector, available seperately | ||
| Front Panel: | Power switch (pushbutton, push-on, push-off), green power indicator LED, red mute indicator LED. | ||
| Rear connectors: | SMA female for antenna, 2.1 mm x 5.5 mm coaxial female power connector, 3.5 mm stereo jacks line-in, line-out, and accessory (external mute switch, external power amplifier, transverter, etc.) | ||
| Dimensions: | 1.1875 x 3.125 x 7.0 HWD (overall) |
#1 by Jim at March 14th, 2011
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need price of the LD-1b KIT. I found the assembled price $285.00 but not for the kit. thank you and 73, Jim
#2 by admin at March 15th, 2011
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Hi, Jim, it’s $209.95 at the Lazy Dog Store, Ebay or Amazon.
#3 by Paul Swanson at April 2nd, 2011
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Peter – I just received my LD-1B kit (ebay purchase – you shipped 30MAR2011) – thanks! Is there any chance I could talk you out of a schematic?
Thanks in advance!
Paul S. Swanson – AA0K
#4 by Bruce Pedersen at August 6th, 2011
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Pete
There are not enough words to express my joy over the LD-1B. Its receive capabilities are amazing so much so that I am actually listening to short wave broadcasts and enjoying it.
Thank you!
Bruce Pedersen AD7AO
#5 by admin at August 28th, 2011
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Thank you, Bruce!
#6 by Bob Wright at October 11th, 2011
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Pete,
Your LD-1B is just as exciting and as much fun as it was when I first become a Novice operator 60 years ago. I believe when the Ham community finds out about the LD-1 there will be a landslide of enthusiastic Hams at your door.
Congratulations for pulling off a truly significant upgrade for us all. It is a joy to operate and I look forward to receiving the Tx.
73, Bob
#7 by Bob Wright at October 11th, 2011
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Should have added my call, WA4GCJ.
#8 by admin at October 11th, 2011
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Bob, thank you very much for your kind comment.
#9 by Bill Noble at February 15th, 2012
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I just purchased the LD-1B from Amazon. and as I was reading this I noticed you did a usb isolation update, just curious if the one I just bought today will have that feature? Thanks in advance Bill Noble KA9GNG
#10 by admin at February 29th, 2012
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Yes! All those sold since that post include USB isolation.
#11 by Rob Kane at March 5th, 2012
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I’m just gettingready to set up my LD-1B2. Can anyone recommend a specific sound card that is known to give excellent results?
#12 by admin at March 16th, 2012
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Rob, maybe this post from a couple of days ago. I hope to post Part 2 tomorrow.