[TenTec] On Noisy Transmitters

[Bob McGraw - K4TAX]

Measurements were done on my personal TS-590.  I repeated this test several 
times over a period of time and obtained near identical results.  A 2nd 
TS-590 was being used at a Field Day site.  It was noted by others that the 
noise increased on their receivers when the TS-590 was in transmit 
regardless of band or mode of operation.  Coincidently, I did have my 
analyzer at the site and observed this unit during transmit.  The results 
were almost identical to those of my personal radio.  These radios were of 
different ages although no production lots or dates were noted.  Rick has 
identified a similar occurrence and incident in Europe with one or more of 
these radios.   Although likely not statistically adequate for the number 
sold, those reliably measured or evaluated show 100% of those show excessive 
spectrum noise when in transmit.

Under advice of council, I will not comment further, only to say that 
Kenwood has been notified and supplied my test results by certified mail 
some months ago.  They have yet to respond.

73
Bob, K4TAX





----- Original Message ----- 
From: "Rick - DJ0IP / NJ0IP" <Rick at DJ0IP.de>
To: "'Discussion of Ten-Tec Equipment'" <tentec at contesting.com>
Sent: Monday, July 07, 2014 4:08 AM
Subject: Re: [TenTec] On Noisy Transmitters


> James, if you join the Elecraft group and read the history files, you'll
> find lots of references.
> One of them was an analysis of the circuitry in the 590, explaining what 
> the
> technical problem was and how Kenwood could have avoided it by spending 
> just
> a little more on better components.
>
> BTW, both incidents I reported on had a pair of 590s, not just one.
>
> Regardless, Bob has measurements of the 590 on spectrum analyzer, showing
> the problem, and engineers have explained what the exact cause is, so it 
> is
> a bit ludicrous to argue statistics here.  Fundamentally, the reason is
> "CHEAP".
>
> If we all cry together out demanding cleaner transmitters, we will one day
> get them.
> But as long as people keep sticking up for the OEMs, they aren't going to
> change anything.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of K8JHR
> Sent: Monday, July 07, 2014 1:39 AM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] On Noisy Transmitters
>
> I put little stock in one test at one site by one group of guys on early
> production units.  I know there are loads of 590s in service in contest
> group shacks and have been used happily on many FD sites, so the question
> becomes one of statistical significance.
>
> Rick reports on just TWO (early production) TS-590s at a German contest 
> club
> station.  I know Bob had a similar experience with one or two 590s at a US
> FD site.  But I have NOT been presented with credible reports from any 
> other
> group and this has not been discussed to ANY degree on any of the 3 TS-590
> web discussion groups - and I moderate one of those lists daily.
>
> I do not dispute these stories ... I only wonder whether 4 or 5 reported
> cases is statistically significant.  A great number of 590s are playing 
> well
> among other rigs in a great number of shack world wide without problems. 
> My
> 590 was nice and quiet and played well with other rigs close by.  I cannot
> get too excited over this until I see more
> (credible) data and (actual) documented cases.  There appears to be far 
> more
> than 12,000 units in service, and this is just not an issue among actual
> owners.
>
> (He said reaching for his Teflon suit.)     ;-)
>
> ------------------ JHR -------------------------------
>
> On 7/6/2014 6:50 PM, Darrell Bellerive wrote:
>> Would you publish this list?
>>
>>
>> On Sunday, July 6, 2014 4:07:52 PM Rick - DJ0IP / NJ0IP wrote:
>>> Every now and then we run these tests at one of our multi-multi
>>> contest stations on all the transceivers we can find.  There we have
>>> lots of antennas but generally pretty far apart.  If one of the
>>> radios causes noise to all others, it gets banned from the site.
>>> Most of the low cost Japanese radios have been banned because they
>>> disturb the other 5 bands when they transmit.
>>
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