Hytera PD365 programming

I recently acquired a second-hand Hytera PD365 DMR radio.

Hours of trying to program the radio learned me that this is a bit of an odd one out in the Hytera range of radios. I spent *a lot* of time trying to connect it to my computer to read out the memory and program it. I found a lot of information spread out on the internet, but lots of it is not applicable to the PD365. You’ll find remarks such as “There’s a different driver for the PD365.” but which one to use isn’t marked. There might be a page dedicated to the PD365, but I haven’t found it.

I’m not claiming all of this is 100% correct and this is certainly not a definite “user guide to the Hytera PD365”, but there are a few things I learned that might save someone a bit (lot) of time.

First off a some info on my specific handheld, which might be important:

  • Frequency range: 430-470MHz
  • FW version: A1.02.09.001
  • Baseband version: V2.01.03P8

Things I found out:

  • There’s different versions of the PD365, covering different frequency ranges. Codeplugs cannot be interchanged between these two versions. (thanks to ON5LUC for pointing that out)
  • To program the device, you’ll need CPS (customer programming software) from Hytera. You’ll find that you can download it on a few sites. However, the versions you’ll find easily don’t work with the PD365. For this specific hand-held, version V8.06.01.010 and others in the v8 range will not work. You’ll need a version in the v2, such as V2.05.03.002.EM5
  • Getting the programming cable to work: I lost a lot of time trying to connect to the PD365. Since I found different drivers for the programming cable (without any explanation on what’s the difference and when to use which), and even batch files to remove previous versions of drivers, I figured there was a driver issue on my computer. Trying on another one had the same result. And another one. I kept trying to get Windows 10 to use the drivers that I found mentioned on different websites instead of using generic Prolific drivers. However, the CPS didn’t indicate any available port to connect to.
    After all, this wasn’t necessary. After installing and using the v2 CPS program, I could select the serial port that was assigned to the programming cable using the Prolific drivers (currently using version
  • Reading the configuration from the hand-held instantly worked after connecting the hand-held to the programming cable and using the correct CPS. After making changes and trying to write to the hand-held, I had some more issues. The hand-held would display an error message, and the software would display a message box. After clicking OK in the message box, the software would force close without any further messages.
  • Upgrading the FW: there is a v1.06.01.001 FW version available. To use it, install the software package. Then disconnect the radio from the USB cable and remove the battery. Press the button under the PTT button (the round one), and place the battery. The red LED will blink. After about 3-5 seconds the LED will light solid. Release the button. The display on the HT is blank. Connect the USB cable. Start the software, select the correct COM port and click upgrade. The process takes a couple of minutes during which the software informs you multiple times that different phases of the upgrade are finished. Just wait. “Updating the firmware chip, please wait…” takes a long time and it might seem like something is wrong.
    Just wait. If all goes well, the process will end with ”
    However, the first time I tried this, the process ended with an error message after upgrading the FW chip (“Update the firmware chip failed”, the progress bar was at 72% at that time). However, after powering the radio on, the new fw seemed to be installed. Baseband version is now at V2.01.03P8_A.
    I tried the process again with the same result.
  • After upgrading I could write from the CPS software to the radio. The radio restarts after successful programming.


Current status

I’ve managed to program the local analogue repeater so that I can use it. I have not yet managed to get the DMR to work, probably most likely because I haven’t spent enough time learning about the DMR network and how it should be configured. Still, I expect the radio to work and that I will manage to get it configured properly.


Some useful links (some in Dutch):




HP 8640B Signal generator. Part 1: initial state


I recently acquired a HP 8640B signal generator. A quick summary of the specs shows why this is an interesting piece of equipment:

  • 500kHz to 512 MHz (option 2 adds a doubler, extending the range to 1.024 GHz)
  • Available power range is -145dBm to +19 dBm, withing +0.5dB across the full frequency range
  • Extremely low phase noise (less then -130 dBc at 450 MHz, 20kHz from the carrier)
  • Fine tuning (when in locked mode): >+/-20ppm
  • Integrated counter, switchable between the internal generator and an external input
  • FM and AM modulation
  • Beautifully engineered (but that’s just an opinion)

The retail price in the mid seventies was around 12.000 USD.

My unit has the frequency doubler (Option 2), and a serial number starting with 1522U, meaning it was produced in 1975 (add the first two digits to 1960), week 22 in England. As far as I know this is probably in a factory in Erskine, Schotland.

And obviously it doesn’t work as it should. At first sight, the apparent issues are:

  • The unit has cracked gears (which is a common issue)
  • Intermittent power rail faillures
  • Counter shows all zeros (seems to work with external signals when the -5.2v rail comes on)
  • No output power on the front connector
  • “Reduce FM vernier” is lit

At least, the display shows something, and there are some lights. More lights = better.


It needs cosmetic work as well: there is flash corrosion all over the metal parts, and some kind of brown gooey residue. One of the modulation dials has a broken knob. Plastic has yellowed, the vinyl needs work. The list goes on.

First issues to be solved (apart from cleaning while waiting for components):

  • Fix -5.2V power rail (A18U1 needs to be replaced)
  • Replace burned diode on the A12 Rectifier board, possibly using an external rectifier placed on a custom made board
  • Zener diode A20VR3 (+44.6V LED) seems to have been burned, or is at least moving in that direction

After those issues have been solved, the RF path can be checked.

The following sources of information have been of great help so far:

  • The people at the great Yahoo HP/Agilent Test Equipment newsgroup
  • Various blog posts, I will list them where apropriate
  • The US Army TM 9-4935-601-14-7&P “PATRIOT AIR DEFENSE GUIDED MISSILE SYSTEM” Operator, organizational, direct support and general support maintenance manual

HP 8711A: modifications, tweaks, refurbishing

I recently acquired a fairly well preserved HP 8711A network analyser. As sold, this is an economy model, offering only scalar measurements (although vector information can be acquired through the HP-IB bus).


What makes this unit interesting, is that the hardware is the same as the never released 8712A, which has vector capabilities. Some changes in the bootrom allow the user to “convert” the unit, making it behave like a full fledged VNA.

Credits for this rom modifcation go to Massimo Porzio (IK1IZA). As far as I know, he is the one who took the time to figure this out. I also found a lot of information on the site of Michal Lewczuk (SP2XDM).

Before doing anything, a backup of the correction constants was made to disk.

Unit boot screen as received:


I used the TL866 USB High Performance Programmer which can be bought online for around €40. Download the software while you wait for the package to arrive, download speed reminded me of the late nineties…

The bootrom with attached label (on the A1 CPU board, removal of the CRT/PSU module is necessary):


Contents of the ROM at address 0x1FFA0 prior to modifications:


After modifications:


New bootscreen (SRL and fault location enabled as well):


Smith chart as proof of vector capabilities:


CRT realignment and brightness setting

Some adjustments on the CRT were done:

  • When looking from a normal viewing angle with the unit placed on the desk, the alignment of the options on the right of the screen seems “off” when compared to the location of soft buttons next to them.
  • The screen was rather dim.
  • Sizing of the display compared to the cutout in the front panel could be enlarged.

I marked the locations of the front panel cutout and the top and bottom buttons on the CRT:


After disassembling the CRT/PSU module and attaching the PSU to the back, followed by some creative cabling, the unit was powered on while leaving access to the alignment potmeters:


The positions of the potmeters before adjustment were marked:


After adjusting the height/width and brightness, the screen looked much better.

Power supply patch

According to a ECN from HP, units with serials between A00000 and 3325A00941 need a 3W, 680Ω resistor between pin 9 and 16 on J5 in the power supply.



Resistor added and pcb cleaned:


Speaker “modification”

The A models of this network analyser had an issue where noise would get into the audio circuit, causing a high pitched, squeeling noise. When used in a silent environment this was really bothersome, so I first tried replacing the speaker by a version with a slightly different resonant frequency.

This didn’t help enough, so I ended up with this ugly (but fully working) solution:


Cleaning and restoring the unit

A lot of time was spend cleaning and restoring the unit, as to give it as much of its original appearance as possible.

  • The inside of the case was cleaned, connectors on the backplane (which are notorious for causing problems with this model) were cleaned using a combination of MEK, IPA, soda, warm water, patience and lots of love.
  • Front panel and keypad were cleaned, and the yellowing of the plastic due to age and UV was reversed through the use of high concentration hydrogen peroxide. Dents, holes and cuts were fixed.
  • The vinyl was cleaned, restored and treated.
  • Internals of the disk drive were cleaned.

Documenting this is worth a separate post.