[TenTec] OT: 7300 buy back program

Tue Aug 16 08:55:56 EDT 2016

Flex has never been shy about touting their own perfection, ala' the 2 hour on-air infomercials on 20 meters every Saturday afternoon.

And you still need a PC to run one…

Apparently someone has devised a way to get more than 96 dB dynamic range out of 16 bits and my congratulations to them for having successfully violated the laws of mathematics.

I wish they would apply that to the sub-par Compact Disk format with which we are stuck…

Gary

> On Aug 16, 2016, at 4:25 AM, Barry N1EU <barry.n1eu at gmail.com> wrote:
> 
> The argument that the current 16-bit digital sampling offerings (Flex 6K,
> ANAN-100/200, MB-1, etc) are insufficient in bit depth and sampling rate
> doesn't hold water IMHO.  Besides my own experience of no observable
> overload during major DX and 160M contests, here are a few more tidbits to
> consider:
> 
> http://www.eham.net/ehamforum/smf/index.php/topic,110479.0.html
> 
> https://community.flexradio.com/flexradio/topics/adc-overload-myths-debunked
> 
> etc etc
> 
> Barry N1EU
> 
> On Tue, Aug 16, 2016 at 7:43 AM, rick at dj0ip.de <Rick at dj0ip.de> wrote:
> 
>> EXCELLENT Gary.  Thanks.
>> 
>> I only disagree on the timeline.  I don't think it will take so long.
>> 
>> The MB-1 from Sun SDR or Sun Expert (not sure which brand they are
>> pushing) "claims" to be what you described, but it costs $5K.  However
>> prices will drop rapidly as soon as competition is there.
>> 
>> Within 3 years we will have it.
>> 
>> In the year 2020, SDR with knobs a'plenty.  (no computer required)
>> 
>> BTW, has anyone actually seen or used the MB-1?
>> I haven't heard a single user review yet.
>> 
>> 73 - Rick, DJ0IP
>> (Nr. Frankfurt, Germany)
>> 
>> 
>> 
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Gary J
>> FollettDukes HiFi
>> Sent: Tuesday, August 16, 2016 7:23 AM
>> To: Discussion of Ten-Tec Equipment
>> Subject: Re: [TenTec] OT: 7300 buy back program
>> 
>> I agree that discussion of the general concept of direct conversion and
>> SDR is relevant to this reflector regardless of brand. At some point, all
>> radios will be of this design because it will be the cheapest possible way
>> to produce a radio.
>> 
>> I have not used the 7300, likely will not. I’d prefer an Omni 6+ that has
>> SSB audio I can tolerate, a notch filter INSIDE the AGC loop and a
>> standalone bandscope.
>> 
>> The topic of digitization at this level was discussed ad-nauseum back in
>> 1983 and 1984 as Compact Disk technology was just beginning as a
>> “replacement for Vinyl records”. Things did not quite work out because the
>> number of bits in the audio samples and the sampling frequency (44.1 KHz)
>> required compromises that people with musical ears could easily hear.
>> 
>> The move towards direct digital conversion and SDR is a replay of the same
>> thing. If you don’t use enough bits in the sampling process, and don’t
>> sample often enough, there is not sufficient dynamic range to allow for the
>> wide variations in signal strength experienced on HF.
>> 
>> Most good operators can copy signals that are within a few dB of the noise
>> floor, especially in CW. These signals can easily be S1 or less on most
>> good receivers, depending on band noise.
>> 
>> The strongest signals (particularly in Europe with the big shortwave
>> stations) can easily be 100 dB over S9 (48 dB) for a total signal dynamic
>> range of 148 dB. 16 bit sampling only allows for 96 dB dynamic range. In
>> order to get 148 dB dynamic range (3 dB dynamic range improvement per bit)
>> you would need 32 bits minimum to handle the range.
>> 
>> Keep in mind that, even though you are not LISTENING to that 100 dB over
>> S9 shortwave station, the receiver is still seeing it as this is part of
>> the spectrum that the DSP is trying to unravel to select your signal of
>> choice.
>> 
>> When the input to a digital device exceeds its dynamic range, the results
>> are far from linear so artifacts, not really unlike severe overload in
>> analog circuits, are heard, but often to a far worse degree than with
>> analog systems.
>> 
>> By analogy, the simple harmonic distortion produced in Vinyl by
>> overdriving the cutting lathe were far more tolerable to the listener than
>> the nasty aliasing that occurred from under sampling of audio signals in
>> early CD recordings and the non-harmonic distortion that arose from the
>> steps of quantization error with only 16 bit amplitude range, especially on
>> soft notes whose bit level resolution was maybe two or three bits.
>> 
>> As manufacturers learn this (Ten Tec included) things will get better, so
>> long as the focus is on worst case receive scenarios. More bit depth and
>> faster sampling rates will improve direct digital receivers to a point that
>> they will be better than their analog counterparts. The marketplace will,
>> however, dictate when that occurs.
>> 
>> 24 bit 96 KHz sampled audio has been available technically for 15 or 20
>> years using the DVD platform, but I have yet to see a disk that can offer
>> it even to my damaged hearing. The marketplace preferred iPod(YUCK!) and
>> MP3 (double YUCK!) because you could put 2000 “songs” onto a chip the size
>> of a grain of rice, 100% of the songs being unlistenable sonically.
>> Quantity wins out over quality for most people, especially if it’s cheap.
>> 
>> Accepting a product with the obvious failings of poorly implemented direct
>> detection creates a market for the junk (translation - entry level) and
>> delays introduction of top performance designs.
>> 
>> PS: I don’t want to have to have a PC running just to sit and listen to 20
>> meters or to see a full scan of the band while I am doing something else.
>> The only reason I don’t have an Eagle today is that getting a bandscope on
>> it is a big PITA and I still need to have the PC running to use one.
>> 
>> It will be a long time before TenTec or anyone else will offer a top
>> performing fully digital receiver, with knobs and stand alone, so long as a
>> trinket market exists for the performance level offered in the 7300.
>> 
>> Gary
>> 
>> W0DVN
>> 
>> PPS: There is still no digital camera anywhere with the color depth to
>> match old fashioned Kodachrome 64. 8 bits per color? Not enough! Same
>> cause, same result.
>> 
>>> 
>>> I am wondering about the same sorts of things.  I bought a new Omni VII
>> during the Fire Sale.  I got it with the optional 300 Hz CW filter.  Once
>> the novelty wore off, I started getting annoyed by having to push a menu
>> button, then scroll to a setting, and then select something like the
>> setting the keyer speed, and do some other actions, just to do what a lowly
>> knob does on my Corsair II and my MFJ keyer.  So, that radio has found a
>> new home.  The Argonaut VI has a complex system of making adjustments, too,
>> but it is much easier to use than the Omni VII, and seems to have a better
>> receiver.  I am using the Corsair II on HF again, and am starting to see
>> why those people who also own one, or have an Omni VI, prefer them to the
>> newer rigs.  This was brought home to me rather abruptly with the recent
>> threads on keeping Orion II rigs functional.  With a rather obstructed trap
>> vertical installed on a hillside, I am not going to set the contesting
>> world on fire no matter what radio or radios I use.  So, I can still prefer
>> high performance radios that are getting on in years, like me, and are much
>> less complex to use.
>>> 
>>> Your Mileage will Most Certainly Vary...
>>> 
>>> 
>>> Steve WA9JML
>>> 
>>> 
>>> On 8/15/2016 1:16 PM, Mike Bryce wrote:
>>>> I have a hard time handling over $1500 for a radio and being told it’s
>> ‘entry level.’ Nothing like scaring the bejesus out of a new ham who after
>> spending all that money for a rig, he/she ends up with ‘entry level’ radio.
>>>> 
>>>> Does one really need a $4k/$5k radio to have fun with?
>>>> 
>>>> How in the world did you guys survive contesting using the Triton IVs,
>> the TS-520s, the FT-101s, and the HW-101s?
>>>> 
>>>> 
>>>> Mike WB8VGE
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>> 
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