Manager


Manager - NA4M
Manager Notes

Reviews For: N3ZI DDS2 DDS VFO KIT

Category: Ham Radio Kits

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : N3ZI DDS2 DDS VFO KIT
Reviews: 21MSRP: 79.00
Description:
This is a direct digital synthesized stand alone VFO kit capable of producing a clean sine wave up through 34 MHz.
Kit includes eveything needed to build the VFO and control it though its encoder, 2 momentary pushbuttons, DC in and RF out. Capable of step sizes as small as 1Hz and display resolution to 1 Hz. 10 memories, 2 VFO's, software calibration, RIT, RS232 capable, and programmable IF's.
Product is in production
More Info: http://www.pongrance.com/super-dds.html
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00215
KG4RUL Rating: 2020-01-14
Works Well Time Owned: more than 12 months.
I am using mine with an Hf-Signals, BITX40 transceiver. The kit went together smoothly and worked the first time.
K0IZ Rating: 2020-01-13
Works well in homebrew transceiver Time Owned: 6 to 12 months.
I purchased the "vintage" version and use as the VFO in a neo-vintage 20M SSB transceiver (tubes). Output is about 0.25V PP so requires a buffer amp of some sort to adequately drive a tube mixer. I made several changes to the stock board:
1. Replaced 80Mhz Xtal oscillator with a TXCO from eBay for high freq stability. Paid $15. TXCO fits on board same as original
2. Installed headers for LCD and encoder.
3. Used optical encoder (128 step) purchased used on eBay
4. Reprogrammed microprocessor using TeraTerm software. Parameter 8 was 0.010, changed to 0.000 to eliminate contact bounce (needed for stock encoder but not for optical encoder. Important for quickly changing freq.
5. Reprogrammed parameter 9 from 0.002 to 0.001. With my 128 step encoder this gives 2.56 Khz per turn and 25.6 Khz per turn which I preferred. Without this change the 128 step would have been 1.28 and 12.8.
Changed the horrible RCA output jack to an SMA jack.

I highly recommend this kit.
WB0FDJ Rating: 2019-05-18
Great product Time Owned: 0 to 3 months.
I own two vintage radios, a HW-16 and a Johnson Viking Adventurer. Both chirped on most crystals. I was looking at picking up a used HG-10 or similar tube VFO. But they are going for over $100 and some of them need a lot of TLC. So for $79 I ordered Doug's newest DDS VFO.

This is a nice accessory. It went together easily enough (carefully following the step by step check outs) but the LED didn't show any activity. A couple of emails and the problem was found and fixed. My fault. Then I went to Dr Greg Latta's home page and found that he had built this same VFO and has excellent documentation on his building steps, which I followed. If you get one of these visit his webpage.

https://faculty.frostburg.edu/phys/latta/ee/vfo/vfo.html

Adding a buffer amp, built Manhattan style and a step up voltage transformer allows me to drive both old rigs to the highest frequency. Two big advantages: accurate frequency readout and no chirp at all. These are now my daily drivers and I am considering getting another VFO to use with DC receiver projects. Highly recommended for quality and support.
KA9P Rating: 2018-10-20
Very nice product Time Owned: 3 to 6 months.
Great instructions, easy build, very nice results. I'm using mine as a testbed vfo for 602/612 projects, and as a sig generator for HF, nice to have a sinewave generator rather than the SI series of square wave stuff. Only drawback is the relatively low level output compared to the Si series of chips, but knew that going in and a buffer amp is easy enough for driving higher level mixers and test gear.
K3MD Rating: 2016-01-11
FB Time Owned: 0 to 3 months.
Ordered this after working one on the air. The DDS went together well with my limited kit building skills... the buffer amp did not work as sent out, redesigned with a more conventional design, works fine. Put it in a little plastic case, works well with my Knightkit T-60 and homebrew 6MJ6. Much better than my Heathkit HG-10B!!!
W7MBR Rating: 2015-05-08
Terrific Product Great customer service Time Owned: 0 to 3 months.
I liked the first one so well I had to order another one. I built a little buffer amplifier circuit and the DDS VFO does a great job driving my vintage tube radios. They are now completely stable with no chirps on CW with accurate frequency readout. The kit isn't that hard to assemble either with the included quality components. Although the N3ZI DDS VFO Manual mentions it, here's an easy way to solder in that little surface mount Chip included in the kit. With a medium heat fine tipped soldering iron simple run the tip and solder across all of the pins in one complete sweep letting the solder overlap. Then, with good quality solder wick, simply lay it across the pins and remove most of the solder. Check with a magnifying glass and make sure there are no solder bridges. Repeat if necessary. It's almost impossible to remove too much solder as the pins on the chip will remain secured to the PC board.
VK2BEN Rating: 2014-10-11
Great value-for-money and featureset Time Owned: more than 12 months.
I use these devices for accurate and stable frequency generation in my HF APRS tracker projects.

A particularly useful feature (for my purposes) is the simple RIT offset that can be keyed at at least 300baud.

I use this feature in conjunction with a Byonics TinyTrak3 (TT3) fitted with a custom FSK chip (Available from Byon).

Endgame: it works so well that I have a backlog of orders for trackers ;-)

Looking for xtal-like stability (or better?) and frequency agility? Look no further than N3ZI.

Disclaimer: I'm just a happy customer.
VK5GI Rating: 2013-12-18
A really useful tool Time Owned: more than 12 months.
Doug should be given the Nobel Prize. His DDS VFO kits are promptly shipped, reasonably easy to construct and the bottom line is that they WORK! I do a lot of home brew, and use N3ZI dds vfo in my rigs exclusively. Why shouldn't I? I have had nothing but success with them, and if it ain't broke, I sure as hell ain't going to fix it! If you are into homebrew or restoration projects, I really recommend Doug's products.
KS1U Rating: 2013-11-22
Rock Solid and Precise Time Owned: more than 12 months.
I've been home brewing rigs for nearly 50 years. In the old days my equipment relied on the patience of the other operator to slowly follow me as I drifted across the band. As the years progressed I settled on a Vackar VFO in a heterodyne configuration, which provided fairly accurate and steady service, but at the cost of time, size of device, number of components and cost. N3ZI has a small, steady as a rock, precise vfo with more features than most people will need. It is priced inexpensively and goes together quickly. My latest home-brew project (a 30 meter CW XCVR) uses his latest kit, you can see a photo of this admittedly unusual looking modular radio on my QRZ page. The vfo is easy to program with buttons on the vfo or with a computer and makes operating home-brew rigs a pleasure. No worry about drifting in frequency or wondering what frequency you are actually on. If you are moderately competent with solder and and iron, you'll have no trouble putting this together in one evening. This is the second one I bought from Doug and I'll be placing an order for another one for my next project soon.
AE4GM Rating: 2013-10-21
GREAT VFO Time Owned: more than 12 months.
I always wanted to build a transceiver from parts and different kits. The N3ZI DDS VFO made it possible. I use it to drive the kitsandparts.com 5 watt cw amp and the Tentec 1056 DC receiver. It is set up to transmit on the dialed frequency and has an adjustable offset when not transmitting that goes to the DC receiver set at a 600 hz difference. It works wonderfully. No drift and very reliable. I do have to reseat the main chip on the board from time to time, though. My rig is set up now for 20, 30, 40, and 80 meters. A picture is on QRZ.COM under my call sign AE4GM. Doug Pongrance's customer service is also super.