[TenTec] OT: 7300 buy back program

[rick@dj0ip.de]

Well now I will disagree with Jim "slightly".

I don't think Icom over-sold the product;  Joe Ham overestimated the radio.

I think they let their wishes run away with their understanding.  

As a kid I drove a VW Beetle; always wished for a Porsche at the price of
the Beetle, but alas it never came.  
It was wishful thinking on my part, just as it was wishful thinking on the
part of our fellow hams.
I believe Icom has always defined this as an entry level radio to the direct
sampling world.

AND, if they ever bite the bullet and address the dither randomization
problem, perhaps it will become a decent radio.
It is possible.  ANAN had the EXACT same problem in the beginning and they
used the exact same ADC in the front end.  Took them one year to optimize
it, after Rob Sherwood pointed out the problem to them.

It remains to be seen if Icom will even admit there is an issue, let alone
address it.
After all, if they make this radio too good, how will they sell their 7600
DSR replacement?

PART II:  Front End Overload;  Again it is a dither issue to help cope with
strong front end overload.  However I am breathing down the neck of "the end
of my understanding" for this new technology here.  Now that the 40m
broadcast stations have moved out of our ham bands, a carefully designed
preselector can help a lot.  The problem is, nearly every direct sampling
receiver I know of does not have such a BPF except for the Flex 6500 and
6700, BUT NOT the 6300.  The second problem is, our Region 1 40m band ends
at 7200 with B'cast stations above that. In the states (Region 2) it goes up
to 7.3 MHz.  BEST CASE we would have two versions, one for the states with
300 kHz bandpass and one for EU with 200 kHz bandpass.  I don't have a clue
about condx in Asia.  Won't comment on that.

Personally I built a "tunable" 40m preselector nearly 40 years ago.  It's
3dB bandpass is just 30 kHz and it easily solves the problem Jim mentioned.
However I know of no source for these.  You'll just have to do as I did and
build your own. 

I have finally obtained a direct sampling transceiver here (no known
name/brand) and am amazed how well it performs compared to my Eagle.  But I
am struggling like a Novice with the computer software control (i.e. HDSDR).
Unfortunately I was asleep at the wheel too many years.  I WILL CATCH UP!

73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)


-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Jim Brown
Sent: Monday, August 15, 2016 6:12 PM
To: tentec at contesting.com
Subject: Re: [TenTec] OT: 7300 buy back program

Barry,

I don't disagree that all mfrs are looking at direct sampling RX, and I
agree that they should be. I'd call that wise investment in R&D. My
assessment of the 7300 is that it's a budget level product that was
oversold.

The fundamental issue right now with that technology is dynamic range with
the available chips, which are in the right price range because of the
volume built for them by cell phones. Guys are making Flex 6700s work in
contest superstations because the serious bandpass filtering they would need
with any radio acts as an RX preselector, limiting the bandwidth of the
spectrum that can overload the A/D. But that won't help in EU or AS, where
broadcasters are in the passband of any practical filter on 40M, and there
are some high power broadcasters close enough to  20M to make it a problem
there too.

I think you've been happy with your ANAN in that regard. Are you doing
anything special to address the dynamic range issue?

73, Jim K9YC

On Mon,8/15/2016 5:22 AM, Barry N1EU wrote:
> I think dealers and manufacturers have stock piles of ALL superhets, 
> not just the 7600.  I think Rick is on the mark that the DEALER is 
> simply motivated to move excess 7600 inventory.
>
> What Rick didn't mention is that there's a fresh rumor making the 
> rounds that Icom is about to announce a direct sampling SDR 
> replacement for the 7600.  That's extra motivation to move 7600 inventory.
>
> The 7300 has changed the game, period.  Icom is sitting pretty.


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