I did apparently succeed in inhibiting transmit on a UV-5RA memory(reports Firmware version BFB297 but above BFB296 may not be updated with each revision) without using a computer. The method used was to set the offset and direction such that you were instructing the radio to transmit on 0Hz. The behavior while programming isn't quite what you would expect, and I initially thought I was unsuccessful, but it still appears to disable transmit.
When actually transmitting, the display should change color to yellowish (depends on menu settings) and the signal strength icon should appear. It will also display the transmit frequency instead of the receive frequency if they are different but won't change if the transmit frequency is invalid. If you have inhibited transmit, display should not change in any way (unless you receive a transmission) other than the backlight may come on afterwards if it was off.
I have included very detailed instructions below. In many cases, those who need to inhibit transmit the most (non-licensed operators) may be those least skilled in operating the radio. Also, even many licensed operators have difficulty programming these model radios even when trying to do something normal.
In the example below, I put 146.850 in memory 126; replace those values wherever they appear with the desired ones.
Some notes on operation:
In these instructions, [MENU] is preceded by [EXIT] to make sure you are starting from the correct state (not in menu). When entering one or two digits after menu as a shortcut to a specific menu item, type those digits quickly or radio will time out. If an instruction says "Repeat" something "until" something, repeat the operation as many times as necessary until you see the correct state on display; as a bonus, the available settings will repeat in a loop so you don't have to catch the correct setting the first time and can see exactly what is changing on the display and which most closely resembles the desired setting (in case you are uncertain about which part of the display to look at). Target value could be in top line, bottom line, mode indicators (mostly above top line), channel numbers (to right of top/bottom lines), carets (to left of top/bottom line). The carets show you whether top or bottom line is active. In menus, the top line shows the menu item name and the bottom shows the value and you hit [MENU] to bounce back and forth between them and repeat [UP ARROW] and/or [DOWN ARROW] to select the desired menu item (if on top line) or value (if on bottom line). Returning to the top line using [MENU] enters a value, pressing [EXIT] before doing so will abort the change. Instead of using arrows to select menu item you can enter a one or two digit (quickly) value while on top line and for some values you can enter digits on bottom line. When entering a sequence of digits, do so quickly as the radio will time out if you take too long; in most cases you can simply repeat the digit sequence from the start as you will be in the same state you were in before you started entering digits though the menu item or value may have changed.
- Consider perform a PARTIAL (VFO) reset to disable any weird or leftover settings that might be written to memory. [EXIT] [MENU]   (show "RESET") [MENU] Repeat [up arrow] until bottom line says "VFO" [MENU] (show "SOURCE?") [MENU] (briefly show "WAIT..."). Warning. If you don't select VFO, you will erase all your memories. Hit [EXIT] to abort.
- Turn of dual watch as it is reported to interfere with programming. [EXIT] [MENU]   [MENU] Repeat [up arrow] until second line says "OFF", [MENU] [EXIT]
- Switch to top line: Repeat press [A/B] until caret points upward
- Switch to VFO mode. Repeat press [VFO/MR] until channel numbers disappear.
- Repeat press [BAND] (if present) until top line shows a frequency in the desired band
- Erase channel 126: [EXIT] [MENU]   (Show "DEL-CH") [MENU]    [MENU] [EXIT]. Subsitute desired channel number for 126 in this and subsequent instructions. If channel is not blank, radio may not save to it and/or will save the second half (TX frequency) instead.
- Set frequency to desired value (example 146.850 =      )
- Set OFFSET to same value [EXIT] [MENU]   (show "OFFSET") [MENU]       [MENU] [EXIT]
- Set duplex direction (SFT-D) to minus [EXIT] [MENU]   (show "SFT-D")[MENU] Repeat [up arrow] until display shows minus ("-") [MENU] [EXIT]
- setting T-CTCSS is probably unnecessary since you are trying not to transmit (but don't rely on repeater not keying up as proof of non-transmission). You could set R-CTCSS if desired and appropriate.
- At this point, you should be able to test before saving. Press [PTT] and make sure the signal strength indicator in the upper left hand corner is not displayed and the backlight color doesn't change to yellowish (depends on menu settings).
- Save first half of settings to channel 126: [EXIT] [MENU]   (Show MEM [MENU]    [MENU] [EXIT] (You can also type in the memory channel number instead of using up arrow). If voice is on, radio will say "receive memory".
- Press [*] to enter reverse mode. Display will not show 000.000 or "R" as you would expect but apparently we are still good.
- Save the second half of settings (transmit) to channel 126: [EXIT] [MENU]   [MENU]    [MENU] [EXIT]. If voice is on, radio will say "transmit memory"
- Press [*] to exit reverse mode
- Repeat Press [VFO/MR] until channel numbers appear on right side of the display (once should be sufficient in this case).
- Select channel 126:   
- Press the [PTT] button and observe the display to see if the signal strength icon shows up; if you have inhibited transmit, it should not. It could also show up (accompanied by sound) if an incoming signal is received at same time.
The insane method of writing to memory twice is a perversion of a procedure required in some other non-chinese radios if, and only if, you need to program an "odd split". Those radios would save the transmit and receive settings when you saved a memory but let you overwrite the transmit setting using a separate write instruction if you needed to program an "odd split". Odd splits were a way of programming transmit and receive frequencies that were not related to one another by a standard offset value or were separated by a very large offset that might be hard to enter into offset setting or that you wouldn't want to reuse for any other channel. Odd splits might even cross band boundaries such as using a cross band repeater.
When I went to save the results in a memory channel, however, I thought it wasn't working. Normally, you have to save, hit REVerse (), save again, and hit REVerse () again to exit reverse; this proceedure is necessary to save both the RX and TX frequencies. But when I hit reverse, the display showed 146.850 and not 000.000. So I thought I had failed. But when I tried to check in on the net, the radio did not transmit (nor complain). And closer inspection appears to indicate it is not transmitting.
I had also tried the split to zero method using SAVE, enter 000.000 as frequency, and SAVE again method (alternative to doing OFFSET, SFT-D, REVerse that you can't test before saving) but it wouldn't accept 000.000 as a frequency.
After you are done, clean up your mess. Set offset back to an appropriate value for the band (000.600 VHF, 005.000 UHF). Set SFT-D back to OFF. Make sure radio isn't left in reverse mode. Performing another partial reset is one way to accomplish this.
If this method fails, you will actually transmit so use a dummy load, a frequency you are licensed to transmit on (or a control operator who is) and state your call sign, or at the very least an unused frequency.
This is an old question but this page is still the top search response.