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Reviews For: SDR Kits QRP-2000 USB synthesiser

Category: Ham Radio Kits

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Review Summary For : SDR Kits QRP-2000 USB synthesiser
Reviews: 2MSRP: from £23.50 (UK sterling)
Description:
A wideband synthesised RF generator kit suitable as a signal source for SDR equipment, transmitters, receivers, test etc etc
Product is in production
More Info: http://www.sdr-kits.net/USB/USB_Description.html
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
0025
KD7RDZI2 Rating: 2009-11-07
outstanding coverage!!!! Time Owned: 0 to 3 months.
This is kit is at least 10 years ahead! There are several models according to the chip that is used. I ordered the LVDS Si570, that offers a coverage from less than 4Mhz to beyond 900Mhz!!!! The output level is 0.7V p-p squarewave into a 100ohm load. I use a homemade preamplifier based on a MAV-11 mmic in case I need more output level.

Adding the mav-11 and a 9:1 transformer, I used it as a LO in my old tube Drake 2-C receiver. Notwithstanding the squarewave (I was suspicious about that!) It works perfectly!!! Possibilities of using this generator are plenty! Using in homemade SDRs, as a LO in nearly any rig, as a laboratory signal generator to test and align equipment, as a LO for downconverters for UHF and beyond!

Now, the kit is contains some SMT tiny caps, they are very small, and a small tip iron has to be used. The other crucial part is the Si chip, the pins are hidden and the solder has to flow to touch the pins. Moreveover the chip is sensitive to statics as the other programmed chip. I soldered it as the last component using a small tip iron disconnecting to the power supply each time and touching a ground before soldering (my little iron is not grounded). It required time to me to build this kit, putting in a nice box with the many connectors, cw, ptt and so on) and to test it carefully. Let's say about 16 hours.

Software worked first time as the kit itself. The only drawbacks of the PCB is that is small with many components close each other. In case a part is mounted wrongly it might be a nightmare to replace it. The board is very well made and the kit is worth every penny. However if this kit were offered assembled wired in a box and tested I would have considered to pay some penny more and have it ready plug and play!!!!




G4IPZ Rating: 2009-08-29
Small but excellent! Time Owned: 0 to 3 months.
I ordered one of the kits following reading about it in the UK SPRAT QRP magazine. This was to be my first foray into working with surface mount technology as well.
The kit arrived within days, and I downloaded the documentation and software from the SDR-kits website.
It was a while before I got around to building it (health reasons) but when I did I guess it was about an hour or so build time.
If you've never worked with SMT devices then make sure you've got a good needle point soldering iron and not a stove top gas burner type!

The pcb is beautifully made and about 40mm by 50mm, all through hole plated, silk screened and pre-tinned.
First off you fit all the SMT capacitors (spares supplied in case you sneeze and one vanishes!) , then all the rest of the discrete components.

Finally, after a preliminary USB test The Si570 smt chip was fitted.

The final test proved I had a problem as I could not change frequency and the USB kept 'bleeping' at me when I tried to.

I found a short (my soldering I'm ashamed to admit) and of course it was beneath the Si570 chip.

Boy is this one resilient chip as, following the recommendation of Jan of SDR-Kits I removed it with a hot air gun.
The short had now disappeared, the chip seemed ok so I soldered it back in and BINGO - one working 250MHz plus synthesiser.

I'm using mine as a PC controlled signal generator in my workshop so I purchased the option with the broadband output transformer.
It's more stable than anything else in my shack or workshop and more than worth every penny.

The downloadable software includes Windows USB drivers, a piece of test software and a really neat simple piece of control software which allows you to have ultimate Hz step control of the output frequency

I recommend this kit without reservation. Excellent stuff!