Playing with DDS frecuency up and down searching for the stations, I found them but wooooooow, DDS frequency should be tuned to F*3 instead of F*4. The only test equipment I have is a frequency counter so I did the following test. I tuned DDS at 4000 kHz and place the counter at one of two 74HC74 outputs. Fine, frequency was 4000/4=1000 kHz.
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- The following documents what I've learned in adapting the IQPro DDS VFO for use as an external VFO for the Drake TR7 transceiver. The ultimate goal is to replace the TR7 internal PTO with the IQPro, but using the TR7's existing RV7 interface was an attractive first step since it required no modifications to the TR7 at all.
- In one of my earlier videos I described making cheap Arduino DDS VFO with AD9850 module. DDS Vfo.
The I/Q DDS is a complete AD9851 DDS, Micro controller, and basic software to produce a simple I/Q DDS signal generator, that can also be used as a VFO for a simple SDR I/Q Radio project. The I/Q DDS is suitable for the very popular Softrock and is easily connected to the I/Q inputs on the FST3253 switching mixer.
- Homebrew Apps. However, there are new DDS kit vfo's out there that have much better specs. The original idea was to build the Pic-n-Mix DDS VFO by In fact everything you could want for an HF controller.
The 20M rig has been updated using a DDS for the VFO (kit from N3ZI with homebrew buffer amp) and have added a PC/Sound Card interface so I can use FT8, MSK, etc. Here are pictures of the front after adding the DDS, a picture of the DDS, and the PC interface that I installed. The red bezel covers the larger hole used for the old display.
- DDS VFO 2. The DDS VFO 2 is designed as a companion VFO for the MST3 transceiver, although it may be used with many other rigs. This is a full kit containing all on-board parts including blue backlit...
DDS-VFO 1-40Mhz, spesifikasi : - AD9850 + 100Mhz clock. - Frekwensi 1-40Mhz - RF signal output 10mW (sesuai untuk diode mixer level 7) - menggunakan MMIC MAR-8 atau MAV-11SM.
- Various homebrew QRP rigs. 2N2/40 Homebrew 40 meter QRP transceiver using twenty-two 2N2222s! ATS-3 QRP rig designed by Steve Weber. It fits in an Altoids case, has four band modules, DDS synthesizer, keyer, and other advanced features. I've had a little fun modifying the crystal filter to my liking.
Build a PIC controlled DDS VFO, 0 to 6 MHz. Click a picture to zoom. The zip archive contains a single file, VFO.EXE. It is a DOS program but it runs fine in a Windows 95/98 "DOS bubble" as well...
- Another possible solution that recently caught my eye is the Arduino/AD9850 DDS combination that may allow one to build a VFO radio for less than $30. That sounds pretty cool. I’ll have to do some more research on this to see if it’s what I think it is. I’m not really sure what this would be capable of.
Jan 13, 2016 · Got myself a $10 frequency counter on Amazon as talked about above. Covers 100hz to 65MHz, runs on ~9VDC and has precision down to 10hz. Connected to the VFO project you can see it is stable right to 10hz! Breadboard currently has a class A RF amplifier taking the 10mw signal from the 3 transistor VFO (top of image) to 135mw.
- Nov 26, 2019 · Until the VFO had “warmed up” and stabilized, there were a couple of CW stations that sounded like slide whistles LOL!. The DDS option is definitely an improvement. Still , I think that perhaps all the BITX40 ever really needed to be a better radio (in it’s class), was a stable analog VFO. One last thing, and this is just my “2 cents”…
I think it has been done on an individual basis. I have seen TS-520’s with digital VFO’s and even homebrew tube transceivers with DDS. But a single Universal DDS VFO for use with boat anchors is a decent perhaps original idea. Though, like AB9LZ says, the concept is not new. I just don’t see serious BA owners modifying valuable rigs this way. The joy of vintage radio (or current homebrew) is in part the clunky analog LC VFO’s.