It isn't the chip that limits the frequency range of the tw1.  It is 
such things as the sensing circuit, response of the diodes, reactance of 
the coupling and so forth.  A lot more complicated than just a chip. 
Think about it, that is why manufacturers like byrd have different 
elements for different bands.  That is why you have to switch bands on 
the tw2 for 2m, 220 and 440.  Diodes and circuits respond different at 
different frequencies.
73s
Butch Bussen
wa0vjr

On Mon, 29 Sep 2008, T Behler wrote:

>    Colin:
>
> Have you or anyone tried that new upgraded chip, and is it worth it?
>
> Also, I agree that it'd be nice if you could get a better chip for the TW1
> that would do at least 2 meters as well.
>
> 73 from Tom Behler:  KB8TYJ
>
> ----- Original Message -----
> From: "Colin McDonald" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, September 29, 2008 7:41 PM
> Subject: Re: a couple of TW1 questions
>
>
>> yes, it means you can upgrade the chip to a better one if you want to.
>> Not all chips are created equal, and for cost reasons, the manufacturer
>> likely uses the lowest grade chip they can get away with.  So, for better
>> stability, and better accuracy, you can buy a higher quality, more
>> expensive
>> chip and swap it out.
>> I really wish it meant you could swap in another chip that would allow for
>> the VHF/UHF ranges in the tw1.
>> 73
>> Colin, V A6BKX
>>
>> ----- Original Message -----
>> From: "T Behler" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Monday, September 29, 2008 5:18 PM
>> Subject: a couple of TW1 questions
>>
>>
>>>
>>> Hi, all.
>>>
>>> Well, I ordered my TW1 talking SWR and Watt meter today from W4RT
>>> Electronics.
>>>
>>> So, hopefully, I'll get it within a week or so.
>>>
>>> I do have a couple of questions though:
>>>
>>> 1.  An upgrade  to the TW1 is discussed on the W4RT web page, but it's
>>> unclear to me as to what the upgrade is.  Here's the quote from the web
>>> page:
>>>
>>> "The TW-1 is microprocessor controlled, and can easily be upgrade in the
>>> field with a simple chip exchange. It requires 11 - 15 volts DC at 200 mA
>>> maximum, but consumes almost no current when not speaking."
>>>
>>> Anyone know what this upgrade is referring to?
>>>
>>> 2.  Does anyone have a text-based manual for the TW1?  Or, is it
>>> available
>>> on icanworkthisthing.com?
>>>
>>> Thanks, and 73 from Tom Behler:  KB8TYJ
>>>
>>>
>>> --
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>> 7:40 AM
>>>
>>>
>>
>
>