Inside The Global Communications HSU-10 437Mhz Update

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Joined: Thu Jun 28, 2012 9:39 am

Inside The Global Communications HSU-10 437Mhz Update

Post by G8DKC » Sun Apr 12, 2015 8:22 am

The HSU-10 comes on the market from time to time, stripped from a MTM400 MPEG transport stream monitor,
the un-stripped version going for quite a few pounds! The HSU-10 is not cheap, and does vary in price.

Being used by some to up convert from 146.5 and now 70 Mhz, to Sat Rx frequencies,
and as it is a stand alone mixer perhaps you can go the other way as well to TX?

Update... having just written the piece, I popped on the 437Mhz Tx and yes that's fine as well,
the " 70Mhz or 140Mhz" on the box is what it was made for, not what it can do! :D

Will need a good pre-amp / amplifier for each frequency, filtering etc.

The local oscillator is stable, as they say on the box, but to keep on frequency you can screw in a bnc socket (hole provided) and by moving or "switching?" a capacitor provide a external 10 Mhz source, there is a LMX2325 to produce the 1Ghz L.O being programmed by a PIC16F48, plus some sort of "diode matrix?" into Pic.

A circuit diagram may give the device far more potential :)

I have added a bnc socket to another blanked threaded hole to bring out the 1Ghz and solderd to pcb pad (no mods needed) for monitoring and external projects.

The device is marked at 24v power input, there are 2 onboard regulators at 5v and 12v, testing it looks happy at 13.8v, but to be safe 14v up to its marked 24v supply voltage.

Inside HSU-10.jpg
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HSU-10.jpg (162.5 KiB) Viewed 2124 times

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Re: Inside The Global Communications HSU-10 437Mhz Update

Post by g8gtz » Mon Apr 13, 2015 5:39 pm

Hi Peter,

Very useful unit but there is another variant around with a variable LO with output from 970 to 2170 that you may be interested in - I've attached a few pictures and a block diagram drawn up by Peter G3PYB - I reckon it may be worth trying a mod on yours to see if it can be made tuneable :-)


Global upconv circuit.JPG
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Posts: 33
Joined: Thu Dec 08, 2016 10:17 am

Re: Inside The Global Communications HSU-10 437Mhz Update

Post by vk5bd » Thu Nov 09, 2017 1:22 pm

Hello Everyone,

I had a bit of a play with the HSU-10 Up-convertor, the base unit is 1Ghz, previously we had changed the Reference Oscillator to shift the output frequency to 1.2Ghz for 23cm ATV use. However this time I decided I would have a crack at reprogramming the PIC16F84 controller, but the one installed was code protected, not liking to be beaten, I wrote my own code for a replacement PIC and was able to get the desired frequency out of the HSU-10, here is a copy for your use if you so desire, it was written in MPLAB IDE v8.83


;This code allows for the frequency of a Global Communications HSU-10 Upconvertor to be changed from 1Ghz to what you need
;This code is for the PIC16F84 chip from Microchip communicating with the LMX2325 PLL Oscillator
;While this code worked fine for changing the frequency to 1.2Ghz, there is no warranty that this code will work for you
;Written by VK5BD - Bevan Daniel
;The formula for determining the Oscillator frequency is given by
;Fosc = (( P x B ) + A) / Fref x R
;Where P is the Prescaler (in this case is 32)
; A is the 7 bit Swallow Counter (not my term, from the datasheet
; B is the 11 bit Programmable Counter
; Fref is the Reference Frequency which is 10Mhz for the HSU-10
; R is the 14 bit Reference Counter (20 is used in this code)
; Fref / R = 10Mhz / 20 = 0.5Mhz
;To determine the vaules for A and B in this example
; (( P x B ) + A ) = Fosc / 0.5 = 1200Mhz / 0.5 = 2400
; B = Integer of ( 2400 / 32) = 75
; A = 2400 - ( 32 x B ) = 2400 - ( 32 x 75 ) = 2400 - 2400 = 0
;The structure of the data sent to the LMX2325 is 18 Bits plus 1 control bit, giving a total of 19 bits long per message
;The Control bit identifies which counters the data will be loaded into, with control bit set data fills the R counter and Prescaler select,
;else the data goes into the Swallow and Programmable counters
;Prescaler and Divider Counter (R) Structure plus Control bit
;Which is 000 (padding bits), 1 (Prescaler), 00000000100100 (Divider Counter R = 20), and 1 (Control bit set)
;To make this suitable Byte length we will use 3 Bytes or 24 bits and pad the structure with 5 appended to the end giving
;which then is broken into each byte (8 bits)
;00010000 or 0x10
;00001001 or 0x05
;00100000 or 0x20
;Programable counter (B) and Swallow counter (A) plus Control bit
;Which is 00010001011 (Programable Counter B = 75), 0000000 (Swallow counter A = 0) and 0 (Control bit cleared)
;Then append the extra 5 Bits
;To make this suitable Byte length we will use 3 Bytes or 24 bits and pad the structure with 5 appended to the end giving
;00001001 or 0x09
;01100000 or 0x60
;00000000 or 0x00
;Hopefully that is as clear as mud ;) well I do hope I have explained it well enough that you can modify the code to suit your own frequency
;Good luck and 73

#include <>
; __config 0x3FF9

iDelay equ 0x10
iLoop equ 0x11
iBitsOut equ 0x12
iByteBits equ 0x13
iByte equ 0x14


org 0x000

start movlw 0x00 ; load W with 0x00 make port B output (p. 45)
BCF STATUS, 5 ; Select Bank 0
CLRF PORTA ; Initialize PORTA by clearing output data latches
BSF STATUS, 5 ; Select Bank 1
MOVLW 0x18 ; Value used to initialize data direction
MOVWF TRISA ; Set RA<2:0> as output, RA2 is LE, RA1 is Clock, RA0 is Data
bcf STATUS, 5 ; Select Bank 0
bsf PORTA,2 ; Raise the LE signal to High
call DELAY
call DELAY
bcf PORTA,2 ; Set LE low to indicate data is about to be sent to the LMX2325
movlw 0x13 ; Set the maximum number of bits to 19 for this message
movwf iBitsOut ; Store the bit count
movlw 0x10 ; Define the Bytes that set the Prescaler and Divider Counter in the LMX2325
movwf iByte ; Store the Byte
Call ClockOutByte ; Send out Byte
movlw 0x05
movwf iByte
Call ClockOutByte
movlw 0x20
movwf iByte
Call ClockOutByte
bsf PORTA,2 ; Raise the LE signal to High to trigger loading of the data from buffer
call DELAY
bcf PORTA,2 ; Set LE low to recieve data into the Buffer
movlw 0x13 ; Reset maximum number of bits
movwf iBitsOut
movlw 0x09 ; Define the Byte to set the Programmable and Swallow counters in the LMX2325
movwf iByte
Call ClockOutByte
movlw 0x60
movwf iByte
Call ClockOutByte
movlw 0x00
movwf iByte
Call ClockOutByte
call DELAY
bsf PORTA,2 ; Set LE high to Load counters from buffer
Circle: goto Circle ; Sending data is done, now just sit here doing nothing

ClockOutByte: movlw 0x08 ; Set number of bits per Byte
movwf iByteBits
ClockOutBits: bcf STATUS,0 ; Clear the Carry Flag (This may not be neccessary but it worked so I have left it in)
rlf iByte , 1 ; Rotate the Byte contents into the Carry Flag
btfsc STATUS,0 ; If Carry flag is clear, skip the next line
bsf PORTA, 0 ; Set the Data pin high as the Carry must have been high
btfss STATUS,0 ; If Carry flag is Set, skip the next line
bcf PORTA,0 ; Set the Data pin low and the Carry flag is clear
NOP ; waste a little time
bsf PORTA,1 ; Set the Clock pin high
NOP ; waste another clock cycle
NOP ; and another just to shape the clock pulse
bcf PORTA,1 ; Set the Clock pin low
decfsz iBitsOut, 1 ; Check how many bits have been sent in this message
goto NotDone ; not enough bits sent yet
return ; 19 bits have been sent, therefore end of message
NotDone: decfsz iByteBits,1 ; have all the bits of the byte been sent
goto ClockOutBits ; more bits of the byte still to be sent
return ; The byte has been sent, go back and get the next

DELAY: movlw 0x02 ; Time Delay Subroutine (Thought was going to need to waste a fair bit of time but proved not to be the case)
movwf iDelay ; Outer Loop set to 2
PAUSE: movlw 0x01
movwf iLoop ; Inner Loop set to 1
DLOOP: decfsz iLoop,1 ; Count down Inner Loop
goto DLOOP ; Still in the Inner Loop?
decfsz iDelay,1 ; Count down Outer Loop
goto PAUSE ; Still in the Outer Loop?
return ; Time's up!

Global Communication
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