[TenTec] Rigs at WRTC

K8JHR jrichards at k8jhr.com
Sun Jul 27 04:24:34 EDT 2014


Thanks Rick.    Man, I just don't get how to sort it all out.  Here I 
find an article on "transmitter noise,"  based on ARRL data, and the 
author ranks the 590 above (better) than the KX3 !   So... I think ... 
great... that looks good.

But then another guy says, nope, it is worse, because that is not the 
same kind of noise.

Go figure.

I am truly at a loss to reconcile all these noise figures.

Is he talking about a different type of noise than you are?   What type 
of noise is displayed in the ARRL product reviews?   Is that the same as 
"phase noise,"  "broadband noise,"  and "close in noise?"    I think the 
ARRL should define and explain those charts in plain English, along with 
the proper technical terms.  I am not finding the ARRL Handbook much 
help... or I am missing it ... duh.   Not that we should not use all the 
proper technical terms - I don't want it dummied down - but it would be 
nice to have a regular guy version also, otherwise Joe Ham and I don't 
get much out of the reviews.

	Back to school, I guess.

Thanks, again, for the leg up.

-------------------------- K8JHR ---------------------



On 7/27/2014 3:56 AM, Rick - DJ0IP / NJ0IP wrote:
> 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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