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RF Transmitter register setting.

Hi All,

To control a RF transmitter, I have to set its synthesizer paramter N:

N = (fTX + foffset) / Xclk

we know foffset and Xclk, it is easy to get N when I set any fTX.

but the problem is, there is a register called:

Local oscillator frequency extension.

It has 2 bits for different range frequency.

Why do I need this?

If chip already know my target frequency, why should I tell him another information...

the point is, I still don't know what is this register for ..

For synthesizer, I have N... so what is that for ....

Best regards, Boki.

Reply to
bokiteam
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Don't you think that would be in the datasheet of the transmitter?

Meindert

Reply to
Meindert Sprang

Reply to
bokiteam

General background: synthesizers used for transceive operation (both receive and transmit) have to change frequency when going from transmit to receive. The amount of change is the IF frequency. LO +/- IF = actual signal you receive.

I'm guessing the synthesizer used in your transmitter allows for receive operation too, possibly irrelevant to your application. (And since when is Boki known to every listen anyway?)

How you use it... it'd help if you told us part numbers! Barring that, hook up a frequency counter, try all 4 bit combinations, and see what happens. I'm guessing that one of the two bits enables the shift, and the other selects the direction of the shift. The IF frequency may very well be fixed (and depends on the application... at low VHF it's probably 10.7MHz but it's possible an entirely different register programs this.)

Tim.

Reply to
Tim Shoppa

Bad product then.

How can we, if you don't provide part numbers.... I don't have any crystal ball available!

Meindert

Reply to
Meindert Sprang

Sometimes I suspect that Boki is part of some highly-compartmentalized R&D operation. Think of it like a spy cell. He's probably not allowed to know the part numbers, and indeed many of the Chinese parts apparently have no data sheets that you or I would be allowed to look at (even though they're made by the billions). Heck, a lot of parts designed and made here in the West over the past couple of decades have useless data sheets too :-).

Tim.

Reply to
shoppa

You will think it again when you encounter that.

Provide part number? I wish I can.

BR /Boki.

Me> > No, no description for that... >

Reply to
bokiteam

Can I use oscilloscope to measure the antenna directly ? ( it was on board on PCB)

Tim Sh> > Hi All,

Reply to
bokiteam

a écrit dans le message de news: snipped-for-privacy@i39g2000cwa.googlegroups.com...

Yes, you can use a scope to measure your antenna. Just put the scope and the antenna side by side. When you got how much fraction of the scope length the antenna is, just check the scope length into its datasheet and multiply it by the fractional number. Voila, you've measured the antenna with the scope.

--
Thanks,
Fred.
Reply to
Fred Bartoli

Well, actually I never encounter that. When I design something, I always have datesheets of IC's/modules etc.etc. at hand. If not available, I simply do not use that part.

What exactly are you designing? Is it business or hobby?

I don't get this. You are using an RF transmitter with some sort of interface. If you don't have a datasheet of that transmitter, how on earth are you going to use that thing. If you do have a datasheet, it is apparently incomplete, but you must have some sort of typenumber of the thing. Right?

Meindert

Reply to
Meindert Sprang

Is that a register input or output? Is it seen at other output pins on your module? It may be for selecting different bands of operation or for controlling/switching/selecting external circuitry such as filters or LO's.

Ken

Reply to
Ken Taylor

I got it, thanks a lot!

BR /Boki.

Reply to
bokiteam

For Tx offset. Ed

Reply to
ehsjr

I guess so...

BR /Boki.

Reply to
bokiteam

RTF datasheet.

--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.  
--Schiller
Reply to
Joseph2k

Joseph2k =E5=AF=AB=E9=81=93=EF=BC=9A

N:

her

What is RTF.....

BR/ Boki.

Reply to
bokiteam

Google for "RTFM". He simply replaced the "M" (Manual) with "Datasheet".

Reply to
Matthias Melcher

Hi fool,

I said there is no description already.

Joseph2k =E5=AF=AB=E9=81=93=EF=BC=9A

N:

her

Reply to
bokiteam

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