[Elecraft] Phase noise

[S55M]

Hello everyone!

>From one debate we went to two different ones.
While on the beginning we were talking about K2's TX noise and birdies on
SSB now we are talking on another subject which is interference of magnetic
fields on K2's behavior.
Let's see the noise and birdies problem first.
I found the surce of birdies is the clock signal (maybe the 4Mhz osc itself
also contributes to this) on KSB2 wich goes from pin 14 on U1 to pin 2 of
U2.This signal is interfering directly to Q2 and some birdies are well heard
on the band HI.
So what i tried to do is simply to shield a bit the path betwen the U1+U2 to
Q2. The result is that the strongest bird (Fc 14.250MHz Fbirdie14.148MHz
went down by 10dB (and i suppose all the others went down for the same
ammount) Maybe 10dB seams little but for me evry dB is important.
Picture of my KSB2 can be found at
http://www.s55m.com/teh/images/ksb2.jpg
Test eq:

K2 itself TX output at transverter port (jumper W6) at +6dBm (for birdies
without modulated signal but checked also with SSB modulation wich do not
affect birdies as far away HI)
RX TS930S on CW 500Hz filter AGC OFF
NF Siemens U2032 Gerauschspannungmesser (psophometer) BW 300-3400 Hz
range -70 to +40dB

73's
S55M-Adi

----- Original Message ----- 
From: "S55M" <s55m at siol.com>
To: "Elecraft" <elecraft at mailman.qth.net>
Sent: Saturday, March 19, 2005 2:46 PM
Subject: [Elecraft] Phase noise


Hello again Elecrafters!

Yes Fraser i saw Your comment but not the comments of others.We are still in
very low number.
Seams that only Europians have the problems with "little" birdies and
noises.
And between Europians S5 is a little country with a lot of ham-radio
activity HI.
In what kind of place do we live is Bob asking?
In a place of 300*300 km (186*186 miles if You are more familiar with that).
And during VHF ctests there are at least 10 stations with full legal limit
power and "average" distance between them is abt 35 miles (worst case 23
miles) what in terms of path loss is "only" -110dB in free space on 144MHz
(there is a line of sight between us !!!).
Now all of us use "Javornik" 144/14Mhz transverters designed by S53WW  and
the situation is not so bad as before with all sorts of stuff.The only
important thing now is to have bullet-proof HF RX (K2 shurely is) and a
clean HF TX.
I will enjoy in comments.And i understand that is difficult to deal with
the problem if you live in MBA (Mighty Big America).


S55M-Adi


P.S.
I was trying to send this several times to the list. Hope that it will get
trough now.
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