Topband: Receivers, Noise Blankers and Key Clicks

[Barry N1EU]

I'll let Mike answer, but I was assuming he was referring to the original 
FT-1000, NOT the MP/MkV.  I've heard many FT-1000(D) transmitters on the air 
that have been burdened by noisy sidebands, and sometimes low level discreet 
spurs.

73,
Barry N1EU


>From: "Brad Rehm" <brehm at ptitest.com>
>Reply-To: Brad Rehm <brehm at ptitest.com>
>To: "Michael Tope" <W4EF at dellroy.com>,"Tom Rauch" <w8ji at contesting.com>, 
><jimjarvis at ieee.org>,<topband at contesting.com>
>Subject: Re: Topband: Receivers, Noise Blankers and Key Clicks
>Date: Wed, 4 Feb 2004 10:11:18 -0600
>
>"...I ran the numbers, and sure enough, an S-9 +30dB
>signal from an FT-1000 would have composite noise sidebands
>that would be 20dB above the rigs minimum discernable signal...."
>
>"...I would sure hate to live close to someone using a rig like
>this...."
>
>73 de Mike, W4EF..............
>
>Mike,
>
>This is a perfect example of what concerns me about the off-the-air
>testing we're doing.  And please understand that I'm not criticizing
>your work.  What you have done is very much like the testing I've done
>with equipment from my company's EMC lab.
>
>The problem: In the 160 contests, I compete with a number of contest
>stations in the Austin area.  Even though my QTH is 45 miles north of
>Austin, N5TW and K5NA, for example, can both deliver full-scale
>signals to my receiver when they direct their arrays toward me.  Yet,
>I've been able to work relatively weak stations within 1 kHz of each
>of them.  And I have never lost the use of large sections of the band
>when they're active and beaming north.
>
>In CQ WW 160, for example, to see if I could do it, I worked an S7
>station that was only 750 Hz above Tom.  My rig is a Mk V with a full
>complement of filters and the IRCI IF and click mods.  (Antennas: 3
>Beverages & an inverted V for domestic 'tests.)  My band noise that
>evening was about S3 on the Mk V meter.  I believe Tom (ten miles
>south of my QTH) was running his Orion at the time with a linear,
>although he could have been using his FT-1000D.  I had no trouble with
>spurious stuff from his signal, which speaks well for both the Orion
>and the Mk V, because phase noise affects both the receiving and
>sending end of the circuit.  He hasn't mentioned having a problem with
>my 500 W signal, so...where's the beef?
>
>I could tell a similar story about Richard, K5NA's, signal in the ARRL
>160 'test in December.  I helped put the IRCI click mods in his radios
>and confirm with a scope that the keying waveform had been
>significantly improved.  No problem sliding up to within a kHz of his
>nearly full-scale signal and making contacts.
>
>If the IMD and BDR measurements mean something, why have I been able
>to do what I've described here?  Working anything within 5 kHz of a 50
>or 60 dB over S9 signal should have been very difficult.  Do our
>measurements really predict how our equipment will behave under actual
>band conditions?
>
>73,
>Brad, KV5V
>
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