[TenTec] Rigs at WRTC

[Rick - DJ0IP / NJ0IP]

James,

One thing for sure, you get an "A" for your willingness to learn and an "A+"
for persistence.
Our emails crossed in the ether.

In my previous email I pasted a quote from Peter Hart.
He addressed the difference you asked about.

The close-in noise is a problem all radios have; how much differs.
Not all radios have problems with broadband noise.

As you can see, Elecraft has figured it out and the man who did it is Wayne
Burdick, N6KR.
He's also the guy that explained why the 7600 and 590 have so much phase
noise.

The close-in noise would be most troublesome at Field Day with two stations
trying to operate on the same band.

For contesting or special event stations with multiple transmitters
operating on multiple bands, the problem that can occur is disturbance from
broadband noise.  Peter addressed this too.

Close-in noise is noise near the frequency you are operating on.
Broadband noise is across the entire hf spectrum.

We can do something against the broadband noise.  By inserting a high-power
bandpass filter in the antenna line such as a Dunestar, ICE, or similar, we
can reduce all interference (including broadband noise) by about 40 dB.  So
with filters, many of the radios with a marginal broadband noise problem are
indeed usable in a multi-TX environment. This includes the 590.

In the meantime, most multi-TX contest stations use these filters. 
Unfortunately it is very difficult to convince Joe Ham that he should insert
a $500 BPF in the antenna line of his $600 radio.  If he doesn't and other
hams live in the near vicinity, he will disturb them.

I personally had this problem at my previous QTH in Munich.
We had 3 hams living on our block, I was in the middle.
Two of us ran legal power, driven by clean transceivers.
One ran a TS-450 barefoot.

We two could run high power on different bands and not disturb each other.
When Guenther was on the air with his TS-450, the noise level on our radios
rose several S-Units.

So, filters can help reduce or even eliminate problems due to broadband
noise.
Close-in phase noise can only be eliminated at the radio causing it.

So Wayne's explanation may not suffice as proof in a courtroom but he
certainly convinced me.
I dunno how others think, but the K3's curve on Jim's chart looked pretty
convincing.
That man knows what he's talking about.

73 - Rick, DJ0IP
(Nr. Frankfurt am Main)


-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of K8JHR
Sent: Sunday, July 27, 2014 8:53 AM
To: k9yc at arrl.net; Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Rigs at WRTC

This is very important.

I asked ARRL Lab Tech Bob Allison about it, and he said the two radios were
in the same class noise wise. He said  "at 100 kHz from the carrier, both
have nearly the same composite noise. This not an issue."

Sometimes you guys talk about "phase noise" and other times "broadband 
noise" as if they are the same thing.   Are they?  Am I on the wrong 
page?  I thought you said the ARRL has data, but other times no.

Mr. Allison's whole message follows, so no one will say I am taking 
anything out of contest.   I was encouraged to press on because he 
seemed to support my position.

Where is the disconnect ?   I am sorry if I don't see it.
I thought I was looking in the right places.

---------------------------------------------


________________________________________
From: Allison, Bob, WB1GCM
Sent: Saturday, July 26, 2014 7:52 PM
To: Allison, Bob, WB1GCM
Subject: RE: Transmitter Noise  Issue  Puleeeze help !

Looking at the composite noise on our web site (Product Reviews by
Manufacturer), the Eagle is a little bit better in the composite noise area
than the TS-590S, but both are considered reasonable. The only time when
this issue would come up would be Field Day, when two transceivers are
trying to use the same ham band; one on phone, one on CW. In such a case,
the stations would likely be at least 100 kHz apart from each other. Thus,
at 100 kHz from the carrier, both have nearly the same composite noise. This
not an issue.

Bob
________________________________________
From: Allison, Bob, WB1GCM
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