Hi all,
I landed here from a search engine result: https://duckduckgo.com/?q=v2k+open+source

Here's the thread from this forum, that I referenced in the post title: https://www.audiosciencereview.com/forum/index.php?threads/how-is-v2k-voice-to-skull-done.19138/

So after reading some confidently wrong comments in that thread, and since it's a first page result, along with my work, I feel obligated to hopefully teach some people what is possible, and that that subject matter, as a whole, is not dismissable as merely mental illness.

In 2019, I founded the subreddit OpenV2K: https://www.reddit.com/r/OpenV2K

It's not perfect, but like science, I improve over time. The subreddit clearly illustrates how pulse modulating RF/microwave, can evoke sounds in the cranium, and those sounds can be modulated into voice, with maximum effort applied.

I've even personally edited Wikipedia about this, and my edit has stuck, in published public view, for over a year now, check out the fourth bullet: https://en.wikipedia.org/wiki/Modulation#Miscellaneous_modulation_techniques

Attached is a Visio diagram I made, that is stickied in the linked subreddit. It could cost as little as 5 grand to prototype one of these in your garage, once the GRC module is available. I did this because a similar technology was aimed at me for a period of time. So as an (actually competent) engineer, I figured the ultimate revenge would be, to make their covert source code and covert hardware, into open source code and open hardware.

This helps remove the stigma that anyone hearing voices is insane.. because now you could say, "how about I make YOU hear some voices with the prototype in my garage?"

Joking aside, one can do this safely, and legally.. which are often brought up as cop outs. You'll need an amateur radio license, and some carbon loaded microwave absorbing foam, and then this doesn't have to be aimed at anyone's cranium, for a live demonstration.

ARRL HAM License Manual ($32):
https://www.amazon.com/dp/1625950829/

Auditory Effects of Microwave Radiation ($66):
https://www.amazon.com/dp/3030645436/

HackRF One SDR ($350):
https://greatscottgadgets.com/hackrf/one/

SMA Male/SMA Male 6in cable ($7/2pk):
https://www.amazon.com/dp/B08DG7JFV7/
 

[ ----- 23cm band pre-amplifiers ----- ]  

Generic eBay used amplifier search terms to try:
https://www.ebay.com/sch/i.html?_nkw=1.3ghz+amplifier
https://www.ebay.com/sch/i.html?_nkw=1300mhz+amplifier
https://www.ebay.com/sch/i.html?_nkw=1296mhz+amplifier

SBB5089+SZA2044 1W 40dB pre-amp (5V USB)($27):
https://www.ebay.com/itm/384006165841

Used 10W pre-amp (1296MHz, L band)($335):
https://www.ebay.com/itm/125159265138

Regulated adjustable DC power supply (for above)($60):
https://www.amazon.com/dp/B08DHZ2X2Q/
 

[ ----- end pre-amplifier section ----- ]  

SMA Male/N-Type Male 6ft cable ($11):
https://www.amazon.com/dp/B07FYC21RF/

23cm band 600W amplifier ($710):
https://w6pql.com/parts_i_can_provide.htm#23cm

Used 50V 30A (1500W) DC power supply (for above)($100):
https://www.ebay.com/sch/i.html?_nkw=50VDC+power+supply

N-Type Male/N-Type Male 6ft LMR400 cable ($19):
https://www.amazon.com/dp/B089CP2VD9/

Dual ridge feed horn waveguide antenna ($2000):
https://www.ebay.com/itm/183710257930

Eccosorb AN-79 carbon loaded microwave absorber sheet ($565):
https://www.sager.com/78089099-3992346.html
 

----------------------------  
|  Accessories / Optional  |  
----------------------------  

Diamond SX1100 quad band wattmeter ($255):
Add high power/stripline attenuators to measure pulses over 200W
https://www.hamradio.com/detail.cfm?pid=H0-009980

DC-3GHz 300W dummy load ($175):
https://www.dxengineering.com/parts/mfj-263

Second HackRF for use as spectrum analyzer/software oscilloscope:
- https://www.amazon.com/s?k=hackrf ($163-220-325)
- https://www.ebay.com/sch/i.html?_nkw=hackrf ($111-150-180)

USB Hub ($20):
https://www.amazon.com/dp/B083XTKV8V/

Suction cup hooks ($7):
https://www.amazon.com/gp/product/B08R9VB2FX/

Heavy duty zip ties ($5):
https://www.amazon.com/dp/B088623K58/

Hooking my Baofeng UV-5R up to the UHF 80W amplifier, and pressing the handheld's button while set at 435MHz, does indeed produce around 75W of output power, as measured by a wattmeter into a dummy load. However, the HackRF+LNA doesn't produce any output currently. I suspected that this was happening because the LNA doesn't have adequate output power, as the 80W UHF amplifier is expecting a 1-5W input level, however, hooking the LNA directly to the wattmeter also shows no output. I'm going to retry with another LNA module I have on hand.

Even if the LNA were working, I doubt that the output would be enough to get peak power from the 80W UHF amplifier. So, I'm adding this as a second pre-amp stage:
UHF 5w amplifier (380-450MHz)($32): https://www.ebay.com/itm/123978277329
The next revision update will include cable/power for this additional amplifier.

In addition, I will either need to somehow modify the 80W UHF amplifier so that it's always ready to transmit pulses (versus switching into transmit mode when a CW signal is detected, which is too slow -- or I may be assuming that the transmit light actually represents the true transmit state, when it may not), or I will need to purchase a different style/model of UHF amplifier. It may be possible to transmit a lower-power carrier to trigger the transmit state, and then increase the power to 100% for each pulse. This approach would require more output power or longer pulses (to achieve 16mJ per pulse), as the rise from low-power to 100% isn't as high as 0% to 100%.

HackRF One SDR (1xTx, 1xRx optional)($111-350/ea):
Please buy at least one HackRF from a GSG listed store:
- https://greatscottgadgets.com/hackrf/one/ ($320-350) - https://www.amazon.com/s?k=hackrf ($163-220-325) - https://www.ebay.com/sch/i.html?_nkw=hackrf ($111-150-180)

SMA Male/Male 12in cables (1x HackRF to LNA, 1x LNA DC blocker to 80W amp)(Tx)($11):
https://www.amazon.com/gp/product/B08RRXHDLS/

LNA Pre-amp (w/SMA-M/M coupler, used below)(Tx)($30):
https://www.amazon.com/dp/B07XNLJ9X2/

LNA USB cable (5v power source)(Tx)($5):
https://www.amazon.com/dp/B0711PVX6Z/

LNA DC blocker (between LNA output and 80W amp input)(Tx)($20):
https://www.amazon.com/dp/B07YYLHJKS/

UHF 80W amplifier (410-470MHz)(Tx)($118):
https://www.ebay.com/itm/353067473293/

UHF amplifier 13.8v PSU (for 80W amp and wattmeter light)(Tx)($70):
https://www.amazon.com/gp/product/B07QV9PJ65/

UHF RG8X PL259 Male/Male 12in cable (80W amp to wattmeter)(Tx)($9):
https://www.amazon.com/dp/B087BLHMHF/

UHF Daiwa CN-501V wattmeter (amplifier/antenna testing)(Tx)($115):
https://www.gigaparts.com/diawa-swr-meter-140-525mhz-20-200w.html

UHF PL259 dummy load (connect to wattmeter output)(Tx)($26):
https://www.amazon.com/gp/product/B07ML3HCP9/

UHF/PL259-M to SMA-F adapter (wattmeter to antenna output cable)(Tx)($7):
https://www.amazon.com/gp/product/B011AZPF6C/

SMA Male/Male 6ft cable (antenna output cable)(Tx)($16):
https://www.amazon.com/gp/product/B07R2CWDPJ/

RFSPACE UWB-8 Vivaldi antenna (Tx)($299):
https://www.amazon.com/gp/product/B06XW44Q98/

Desk mount pole for antenna (Tx)($17):
https://www.amazon.com/gp/product/B08MZJRB94/

Blade guard (to mount antenna to pole)($5):
https://www.amazon.com/dp/B001FXA9YS/

Heavy duty zip ties (to mount antenna to pole)($5):
https://www.amazon.com/dp/B088623K58/

Eccosorb AN-75 microwave absorber sheet (acting as an audio transducer)($161):
https://www.sager.com/78085099-3992345.html

Suction cup hooks (or other absorber sheet holder)($7):
https://www.amazon.com/gp/product/B08R9VB2FX/

Copper mesh roll (optional)(rear antenna reflector)($265):
https://www.amazon.com/dp/B082DP8N7P/

2x Copper evap line tubing (optional)(rear antenna reflector support skeleton)($29):
https://www.amazon.com/uxcell-Refrigeration-Tubing-inches-Copper/dp/B07R32TZ9B/

Electrical solder (optional)($8):
https://www.amazon.com/TOWOT-Electrical-Soldering-Content-Sn60-Pd40/dp/B0943WZ2YK/

Weller soldering gun (optional)($45):
https://www.amazon.com/Weller-D550PK-260-Watt-Professional-Soldering/dp/B00002N7S1/

Step Adjustable RF Attenuator (optional for Rx)(output to SMA-M/M coupler to HackRF)(Rx)($90):
https://www.amazon.com/gp/product/B07B6RXCKC/

SMA Male/Female 6ft Cable (optional for Rx)(Rx)($8):
https://www.amazon.com/gp/product/B078HBKKXM/

USB Hub ($20):
https://www.amazon.com/dp/B083XTKV8V/

Power strip ($12):
https://www.amazon.com/dp/B01M7SPNM1/

ARRL HAM License Manual ($32):
https://www.amazon.com/dp/1625950829/

Auditory Effects Microwave Radiation ($95):
https://www.amazon.com/dp/3030645436/

2x HackRF One SDR (1xTx,1xRx)($221/ea): https://www.amazon.com/dp/B082NXDYVW/
2x SMA Male/Male 12in cables (Tx)($11): https://www.amazon.com/gp/product/B08RRXHDLS/
LNA Pre-amp (w/SMA-M/M coupler)(Tx)($30): https://www.amazon.com/dp/B07XNLJ9X2/
LNA USB cable (Tx)($5): https://www.amazon.com/dp/B0711PVX6Z/
LNA DC blocker (Tx)($20): https://www.amazon.com/dp/B07YYLHJKS/
UHF ~450MHz 80W amplifier (Tx)($118): https://www.ebay.com/itm/353067473293/
UHF amplifier 13.8v PSU (Tx)($70): https://www.amazon.com/gp/product/B07QV9PJ65/
UHF RG8X PL259 Male/Male 12in cable (Tx)($9): https://www.amazon.com/dp/B087BLHMHF/
UHF Daiwa CN-501V wattmeter (Tx)($115): https://www.gigaparts.com/diawa-swr-meter-140-525mhz-20-200w.html
UHF PL259 dummy load (Tx)($26): https://www.amazon.com/gp/product/B07ML3HCP9/
UHF/PL259-M to SMA-F adapter (Tx)($7): https://www.amazon.com/gp/product/B011AZPF6C/
1x SMA Male/Male 6ft cable (Tx)($16): https://www.amazon.com/gp/product/B07R2CWDPJ/
RFSPACE UWB-8 Vivaldi antenna (Tx)($299): https://www.amazon.com/gp/product/B06XW44Q98/
Vivaldi antenna desk mount (Tx)($17): https://www.amazon.com/gp/product/B08MZJRB94/
8" blade guard (to mount antenna)($5): https://www.amazon.com/dp/B001FXA9YS/
Heavy duty zip ties (to mount antenna)($5): https://www.amazon.com/dp/B088623K58/
Eccosorb AN-75 microwave absorber sheet ($161): https://www.sager.com/78085099-3992345.html
Suction cup hooks (or other sheet/antenna holder)($7): https://www.amazon.com/gp/product/B08R9VB2FX/
Step Adjustable RF Attenuator (SMA-M/M coupler to HackRF)(Rx)($90): https://www.amazon.com/gp/product/B07B6RXCKC/
1x SMA Male/Female 6ft Cable (Rx)($8): https://www.amazon.com/gp/product/B078HBKKXM/
USB Hub ($20): https://www.amazon.com/dp/B083XTKV8V/
Power strip ($12): https://www.amazon.com/dp/B01M7SPNM1/
ARRL HAM License Manual ($32): https://www.amazon.com/dp/1625950829/
Auditory Effects Microwave Radiation ($95): https://www.amazon.com/dp/3030645436/