MC145152P2
Does anybody have idea where I can find config diagram for dip switch
of this synthesizer? You can see a picture of whole module on http://www.tvsd.co.yu/synthesizer.jpg . This is a part of Elettronica Industriale SPA uhf transmitter. |
I would try terminate the transmitter in to a dummy load or 30 dB
attenuator, try to measure the carrier frequency with a Frequency Counter. Take some notes and just write down the measured frequency at different settings... You may need a Communications Test Set to decode any Tone Squelch type codes if that's what the Dip Switch Settings are for??? Other than that, sounds like ya could use some documentation... |
On 15 Jan 2005 16:11:47 -0800, (Igor Djokic) put
finger to keyboard and composed: Does anybody have idea where I can find config diagram for dip switch of this synthesizer? You can see a picture of whole module on http://www.tvsd.co.yu/synthesizer.jpg . This is a part of Elettronica Industriale SPA uhf transmitter. Why not reverse engineer the area around the IC? Here is the datasheet: http://www.alphacron.de/download/hardware/MC145152.pdf I would think that if you could determine the frequency at one particular setting, then the other frequencies would follow a recognisable pattern. Alternatively, you could calculate all the settings by determining the main oscillator frequency (pins 26 and 27), the wiring of RA0-2 (are they all grounded or tied high?), and how the N and A pins connect to the switch pack. If you can post these data I believe I can do the calculations for you. - Franc Zabkar -- Please remove one 's' from my address when replying by email. |
On Sun, 16 Jan 2005 18:13:09 +1100, Franc Zabkar
put finger to keyboard and composed: On 15 Jan 2005 16:11:47 -0800, (Igor Djokic) put finger to keyboard and composed: Does anybody have idea where I can find config diagram for dip switch of this synthesizer? You can see a picture of whole module on http://www.tvsd.co.yu/synthesizer.jpg . This is a part of Elettronica Industriale SPA uhf transmitter. Why not reverse engineer the area around the IC? Here is the datasheet: http://www.alphacron.de/download/hardware/MC145152.pdf I would think that if you could determine the frequency at one particular setting, then the other frequencies would follow a recognisable pattern. Alternatively, you could calculate all the settings by determining the main oscillator frequency (pins 26 and 27), the wiring of RA0-2 (are they all grounded or tied high?), and how the N and A pins connect to the switch pack. If you can post these data I believe I can do the calculations for you. I suspect IC12 is an MC12017 65/64 prescaler. The A0-A5 count inputs probably all connect to one end of the switch pack. The remaining switches probably connect to 4 of the 10 N inputs, the remaining N lines being tied high or low. If this is the case, then the frequency step size would be given by Fosc / R, where R is the divider value stored in the MC145152's internal ROM lookup table. For example, if the oscillator frequency is 10.24MHz and the RA0-2 inputs are all tied high, then the divisor is 2048 (see page 6 of the datasheet). This would give steps of 10.24M / 2048 = 5kHz. The total count produced by the MC145152's A & N counters is given by ... Nt = N.P + A where P/P+1 is the value of the external prescaler (64) Hence the frequency generated at the external VCO is ... Fpll = 5kHz . (64N + A) The more general formula is ... Fpll = Fosc / R . (N.P + A) To calculate the actual frequency of the *transmitter*, one would need to know if the next stages involved multipliers and/or mixers. I believe the switches serve a dual purpose. I suspect they also connect to 10 of the external EPROM's address lines. The EPROM probably contains a lookup table of 2-digit UHF channel numbers which it presents on its 8 data lines. D0-3 and D4-7 probably control each of the two CA3161E BCD to 7 segment decoder/drivers. If you dump the contents of the EPROM, you should be able to decode the relationship of the switches to the channel numbers. - Franc Zabkar -- Please remove one 's' from my address when replying by email. |
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