If you are going to do it with a Pic then it seems trivial.
Use the first LO (you may need to buffer it)
Count the freq 45-75 MHz in 2.5KHz steps
Have the Pic subtract the 45MHz offset
Tune the tuner.
I doubt very much that the tuner is going to be of such narrow bandwidth
that the possible 2.5 KILOHERTZ error is significant.
What did I miss?
Martin, HS0ZED
dw wrote:
> Thanks Carl,
> I already have the tuner, and the pic to control it, just investigating
> a way to get frequency info to the pic direct from the Jupiter.
> I've seen screen-shots of your software! Extremely impressive!
> You must have been at it for a few years :)
> It looks pretty mature.
>
> On Sat, 20 Jan 2007 20:59:37 -0500, "Carl Moreschi" <n4py@arrl.net>
> said:
>
>> The AT-200PC autotuner from LDG, when used in conjunction with my rig
>> control software, ends up following the rig without having to transmit.
>> You
>> just have to tune one time on each frequency and then the tuner remembers
>> the settings. My program updates the tuner with a new frequency each
>> time
>> the frequency changes on the radio.
>>
>> Carl Moreschi N4PY
>> 121 Little Bell Drive
>> Bell Mountain
>> Hays, NC 28635
>> ----- Original Message -----
>> From: "dw" <bw_dw@fastmail.fm>
>> To: "Carl Moreschi" <n4py@arrl.net>; "Discussion of Ten-Tec Equipment"
>> <tentec@contesting.com>
>> Sent: Saturday, January 20, 2007 8:23 PM
>> Subject: Re: [TenTec] A question for those who know whats going on under
>> thehood :)
>>
>>
>>
>>> Hi Carl,
>>> Thanks greatly for your response!!
>>>
>>> I wonder if I could monitor the op frequency anywhere inside then?
>>> I'm still toying with the idea of controling an external tunner with a
>>> PIC circuit.
>>>
>>> I used to have this with my old icom, but the Jupiter has no external
>>> band output signal.
>>> I had thought about polling the rs232 with the PIC and then deriving the
>>> band from there.
>>> But then I thought it might be easier to tap onto the op frequency
>>> somewhere inside with the PIC and send some control signal out to one of
>>> the unused ports.
>>>
>>> The MFJ intelli-tuners derive settings from a combination of swr,
>>> frequency and complex Z.
>>> But this requires a tune xmit, as the tuner has no other way of knowing
>>> op frequency.
>>> I guess, If I had to, I could do likewise, but it would be nice to have
>>> the tuner move with the rig when in recieve mode also, like the other
>>> rigs do.
>>>
>>> Thanks,
>>> Duane
>>>
>>> Thanks,
>>> Duane
>>> On Sat, 20 Jan 2007 19:47:58 -0500, "Carl Moreschi" <n4py@arrl.net>
>>> said:
>>>
>>>> The first local osc outputs a frequency of 45 to 75 mhz (45 mhz higher
>>>> than
>>>> the operating frequency) in 2.5 khz steps depending on the operating
>>>> frequency. This frequency is controlled by the onboard firmware. After
>>>> the
>>>> first mixer, this produces an IF frequency of 45 mhz. Then local osc 2
>>>> runs
>>>> at a fixed 44.5425 mhz and converts the 45 mhz IF to a 455 khz IF.
>>>>
>> Then
>>
>>>> local osc 3 runs at a fixed 467 khz and converts the the 455 khz IF to
>>>>
>> 12
>>
>>>> khz. This frequency then goes into the DSP section for detection and 1
>>>> hertz resolution. There is no way to monitor any of the oscillators
>>>> externally and determine the frequency closer then 2.5 khz because the
>>>> fine
>>>> adjustment to 1 hertz resolution is all done in DSP. Such is the nature
>>>> of
>>>> DSP radios. The old analog schemes of the past are gone.
>>>>
>>>> Carl Moreschi N4PY
>>>> 121 Little Bell Drive
>>>> Bell Mountain
>>>> Hays, NC 28635
>>>> ----- Original Message -----
>>>> From: "dw" <bw_dw@fastmail.fm>
>>>> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
>>>> Sent: Saturday, January 20, 2007 5:46 PM
>>>> Subject: [TenTec] A question for those who know whats going on under
>>>> thehood
>>>> :)
>>>>
>>>>
>>>>
>>>>> Hey Gang,
>>>>> Here is a Jupiter (under the hood) question.
>>>>>
>>>>> The local oscillator 'A' , is it continuously outputting the frequency
>>>>> which is displayed?
>>>>> or is it outputting an IF frequency?
>>>>>
>>>>> If answer is yes, it is outputting continuously, the displayed
>>>>> frequency,
>>>>> then next question is.....
>>>>> Is there a way to tap onto a board and monitor the current frequency?
>>>>>
>>>>> Thanks
>>>>> Duane
>>>>> N1BBR
>>>>> --
>>>>> dw
>>>>> dw@sover.net
>>>>>
>>>>> _______________________________________________
>>>>> TenTec mailing list
>>>>> TenTec@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>>
>>>> _______________________________________________
>>>> TenTec mailing list
>>>> TenTec@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>
>>> --
>>> dw
>>> dw@sover.net
>>>
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|