Comments on: Contact Me

By: Mike Waldrop W5RKL

Mike Waldrop W5RKL — Mon, 29 Aug 2022 20:40:53 +0000

Where can I download the script? Maybe I missed where I can download it,

I have the Arduino UNO which you used. I also have a USB Nano.

Is it possible to use the USB Nano instead of the Arduino UNO?

By: Gerald Froehlich KR4BR

Gerald Froehlich KR4BR — Wed, 18 Nov 2020 02:09:23 +0000

Dear Sir I am trying to find out The ID or part number for the gold out put connector used on the0 to 55 mhz DDs made in China and sold on EBAY can you help? thank you for your time from Jerry KR4BR 73s.

By: Willard

Willard — Sun, 24 May 2020 19:43:48 +0000

Hi Rich,

I design and build my own 40 meter receivers to cover 7000 to 7070 kHz. I recently built a kit I got on eBay that is a superhet design from China. It has significant drift in the vfo. I built your Arduino Uno AD9850 vfo and it works well. I will use it to replace the vfo function in this drifting receiver. My question is when I first power up the AD9850 and the Arduino Uno I have to connect pin A5 to ground through the 1K resistor and leave it permanently to make it work. Also, I have to press the switch on the KY-040 rotary encoder a few times to get the 7.150 10 HZ display. Once I get there I am able to dial in desired frequencies. This does not seem normal. Am I doing something wrong?

Best regards,
Willard
WA4VSR

By: admin

admin — Fri, 08 May 2020 15:11:46 +0000

I used a fiberglass telescopic “wind-sock” mast. The brand was JackKite. You can also use an MFJ 33′ version available at most all Ham Radio Outlet’s but it’s a little tall. I found that 31′ works best at least for me.

With a minimum of 4 radials (north, south, east, west) of the same 31′ length and just the 31′ mast with a wire inside for the radial, the antenna can be brought to resonance on the 40M band. Mine tunes well at 7.150mhz. With an auto-tuner at the base (LDG), I am able to tune the top of 75M all the way through 10M with no issue. Works excellent on 20M, 17M, and 15M. I do not have a loading coal. Just the antenna, radials, tuner. Simple.

Rich

By: Henry Cha

Henry Cha — Fri, 08 May 2020 01:33:39 +0000

I am very interested in your 31′ long whip antenna. Do you have a more detailed description of this antenna? Like what telescopic mast did you use? what wire did you use? Is this something that can be purchased? What hf bands is the antenna resonant? w/o tuner? I’d love to have something like that in my backyard.

I have a 17′ tall MFJ-1979 telescopic multiband antenna with a loading coil for 80m and 40m but yours looks a lot more powerful!

Thanks!

Henry, KJ6KQW

By: admin

admin — Sat, 04 Apr 2020 15:29:57 +0000

Check for the correct voltage. Also, if the unit is not a genuine manufacturer part it may be defective. A lot of fake AD9850 chips.
-Rich

By: Normando

Normando — Sat, 04 Apr 2020 01:01:53 +0000

Hi, how are you? My name is Norman, I would like to ask you something about your “AD9850 DDS VFO” that you made long ago.

Replify your circuit and work correctly. I only have a problem, that’s what I think, the AD9850 HC-SR08 module heats up quickly, but, I don’t know if the same thing happened to you. Add a heat sink but the problem persists, you have Any idea what that might be?

By: Jules Marco Feuggelen

Jules Marco Feuggelen — Thu, 10 Oct 2019 05:57:59 +0000

Hi Richard ,
Thank you very much for your free VFO sketch. I made , adapted changed and re-adapeted you VFO dozens times and I’m still wondering about it . No I made a new 6-band transceiver and I use again your VFO.
Problem is : I do not understand the lines ( no knowless ) – ISR(PCINT2_vect){…..
My question : how can I use this lines twice 1 x for increment of the step and another for increment of the bands ( 80 to 6 meter ). Ofcoarse I can use A0 to A5 but I need this ports for other use . How do I adapt this code ( just the ISR , not the upper or lower limit ) Can you help me on the way ? 73 Marco , F8VOA , France

By: Frank WA2NAF

Frank WA2NAF — Thu, 07 Feb 2019 00:06:58 +0000

Hello Richard,
Thanks for the great and very useful project. I am retired and 70 and been a builder for 55 years. Been Using MElabs Picbasic Pro for a decade+ and have built some cool stuff, but the Arduino Family of boards have allowed me to build things that I could only dream of.. and Beyond. I have built the Projects in QST over the last years and found a need for a DDS Signal Generator as I stumbled onto your project. I had all the parts and wired it just like the Schematic and after a few minutes of troubleshooting I got it loaded and working. I had an Old HP step attenuator in 10db steps and put DDS rf into it and could feed my HF rig direct with a pretty low level clean signal. Something I needed. That’s why hams build stuff. Anyhow… Thanks again for empowering us old timers.
WA2NAF

By: admin

admin — Sun, 27 Jan 2019 23:52:40 +0000

Reference this:
https://i0.wp.com/henrysbench.capnfatz.com/wp-content/uploads/2015/05/Keyes-KY-040-Rotary-Encoder-Module-Schematic.png?resize=300%2C183
-Rich