A few other things that come to mind -
1.The audio board A15 is different - now has separate IC's for headphone and
speaker. Also added a extra headphone RF filter- the IC is much worse than
the old 565 for RF on phone leads - but fiklter fixes that.
2.The hardware noise blanker is now discrete instead of the unobtanium
blanker IC in the 565.
3.The power amp now uses FET drivers instead of bipolars.
4. The 15/17 meter LPF has poles added - (that may have been done in later
565's - but is NOT like the web site pdf LPF schematic for either the 565 or
5. They eliminated the extra IF stage for the 250 hz filter (now use a lower
loss 300 hz filter in the 566 ) Elimination of that extra stage supposed to
have helped dynamic range with the narrow filter - might be my imagination
, but I use the 300 hz filter almost all the time - I seldom used the 250 hz
in my 565.I have no measurements to substantiate that , just know how it
6. Couple of minor resistor changes on the 81936 5 volts supply board.(as
well as capacitors - on later 566's)
Probably others - but those pop into my mind --
----- Original Message -----
From: "Martin Ewing" <email@example.com>
To: "Discussion of Ten-Tec Equipment" <firstname.lastname@example.org>
Sent: Wednesday, April 29, 2009 5:20 PM
Subject: Re: [TenTec] Differences between 565 and 566?
I agree it would be nice if we had such an upgrade path, but I suspect
there are changes beyond the CPU board. The local oscillator scheme
has changed somewhat, along with the IF filter selection. There may
be too many boards that have significant changes. In any case, even
the CPU / LCD, when packaged as an after-market upgrade, might cost
$1K. Possibly TT could have offered an Orion 1.5 upgrade (CPU/LCD
only), but then they'd have 3 flavors of firmware to support.
The short answer: If TT thought they could successfully market an
upgrade kit, they'd have done it by now.
I'm a little surprised at the differential between the used Orion I
price and the new Orion II. If I were coming into the market now, I'd
be likely to choose the "I" and save > $2K. Color is nice, and the
new-car smell is neat, but that's pretty steep.
73 Martin AA6E
On Wed, Apr 29, 2009 at 7:31 PM, Adam Wade <email@example.com>
> According to everything I have read and seen so far, it would appear the
> only real differences between the 565 (orion) and 566 (Orion II) are the
> faster, larger instruction set processor chip and the color display plus
> whatever support hardware is needed for color vs. monochrome. There is a
> slight difference in the roofing filters, I am guessing a slightly
> different first IF? Not sure what is changed there, or how significant the
> impact of the change is...
> If all this is indeed the case, then it should be possible to "upgrade" a
> 565 to just about all of the 566 spec, with 566 firmware, by replacing a
> few (albeit not cheap) boards. I wonder how feasible it would be to do
> this conversion, sort of like augmenting one of the Omni models to the
> newer spec... I for one would be interested in at least considering such
> an option for the future. If the cost to retrofit was under $1k, it would
> certainly be something I might consider as a future purchase, and the less
> it cost, the more I'd be willing to consider it. ;)
> ! Adam Wade -==- AF6ME -==- Ten-Tec Orion & SteppIR BiggIR Mk III !
> ! "I write down everything I want to remember. That way, instead !
> ! of spending a lot of time trying to remember what it is I wrote !
> ! down, I spend z time looking for the paper I wrote it down on." !
> ! - Beryl Pfizer -=- http://www.allthings550.com !
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