ref osc clicks, really bothers me

howdy,

after 20days works,i built my k2(4513#)and ksb2,knb2 and dsp option. it
works as a whole,but it clicks and pops while i tune the VFO,every 5khz.

I know it is because of the constrution of PLL/VFO, move VFO over 5khz,the
division ratio of PLL change and the reference osc and the varicap voltage
goes to another end of the pulling range,but it sure be too loud,wihle VFO
change at tuning rate of 1khz,it clicks and pops continuously of s-9,it
really bothers me!

my friend,BD8EB's K2(4514#) clicks too,but more slightly,almost couldn't be
felt in most condition,i took view with oscilloscope at TP3 both, it jump
and flash with my k2 while the ref. osc got to the other end of pulling
range across the boundary,but that didn't occur with 4514#.

below  is voltage and associated frequency of 4513# and 4514#:

4513#(click loudly)
 voltage at Pin1 ofU6:     0v      /3.27v    /7.16v   /8v          
requency of ref. osc(TP3): 12096.36/12095.00/12100.04/12100.41
 
4514# (silent)
voltage at Pin1 of U6:     0v       /3.46v  / 6.61v  /8v          
frequency of ref. osc(TP3):12088.78/12095.03/12100.09/12101.30

the middle two parameter(3.27v,7.16v,12095.00Mhz,12100.04Mhz) are the
boundaries which rig works practically.

and i've check out soldering and  value of components,all seemed ok,what's
the problem? will it work replace L31 with 12uH instead of 10uH ?

anyone who could helps me solve the  problem? and will be
appreciated,thanks.

william/BG8AQA

[hidden email]
2005-01-15

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[Don Wilhelm-3]

William,

Re-check the PLL range on SN 4513 as instructed in the manual.  From the
data you provided, I believe your range is too small - the minimum range
should be 9.8 kHz, and yours appears to be only 4.05.  Yes, the first thing
to try is changing L31 to 12 uH.  Also check to be certain you have the
correct varactor diodes installed, and that they are correctly oriented.
Also be certain the signal path from U6 pin 1 to D16 and D17 has good solder
connections at all points including R19 and RP2 - a bad solder joint along
that path will result in inadequate PLL range.

Re: the slight clicks on SN 4514 --
Noticable clicks when tuning is commonly a result of running CAL PLL without
the bottom cover installed.

Run CAL PLL again.  Be certain the bottom cover is properly installed before
running and the 'clicks' should be reduced to almost non-existant.

73,
Don W3FPR

----- Original Message -----

> howdy,
>
> after 20days works,i built my k2(4513#)and ksb2,knb2 and dsp option. it
> works as a whole,but it clicks and pops while i tune the VFO,every 5khz.
>
> I know it is because of the constrution of PLL/VFO, move VFO over 5khz,the
> division ratio of PLL change and the reference osc and the varicap voltage
> goes to another end of the pulling range,but it sure be too loud,wihle VFO
> change at tuning rate of 1khz,it clicks and pops continuously of s-9,it
> really bothers me!
>
> my friend,BD8EB's K2(4514#) clicks too,but more slightly,almost couldn't
> be felt in most condition,i took view with oscilloscope at TP3 both, it
> jump and flash with my k2 while the ref. osc got to the other end of
> pulling range across the boundary,but that didn't occur with 4514#.
>
> below  is voltage and associated frequency of 4513# and 4514#:
>
> 4513#(click loudly)
> voltage at Pin1 ofU6:     0v      /3.27v    /7.16v   /8v
> requency of ref. osc(TP3): 12096.36/12095.00/12100.04/12100.41
>
> 4514# (silent)
> voltage at Pin1 of U6:     0v       /3.46v  / 6.61v  /8v
> frequency of ref. osc(TP3):12088.78/12095.03/12100.09/12101.30
>
> the middle two parameter(3.27v,7.16v,12095.00Mhz,12100.04Mhz) are the
> boundaries which rig works practically.
>
> and i've check out soldering and  value of components,all seemed ok,what's
> the problem? will it work replace L31 with 12uH instead of 10uH ?
>
> anyone who could helps me solve the  problem? and will be
> appreciated,thanks.
>
> william/BG8AQA
>
> [hidden email]
> 2005-01-15
>
> _________________________________________________________________
> 免费下载 MSN Explorer:   http://explorer.msn.com/lccn/
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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> Elecraft web page: http://www.elecraft.com
>

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be grateful to all who helps me  with the pll click problem  of my k2,thanks to Don/W3FPR,Tom/N0SS and Gary/KI4GGX.

 Apologies for a typing mistake that my ref osc's frequency is 12090.36,not 12096.36 while voltage=0v,so the range is little more than 10khz.

however,it still clicks and pop after i checked all components and redid pll cal after i calibrated the frequency counter at accuracy of 10hz,i suppose it's too close to the up boundary of rang where linearizing begin,so i'm waiting for the replacement of 12uH induct to see if it could give a wider range to avoid the clicks.

       

　73

　　　　　　　william/bg8aqa
　　　　　　　　[hidden email]
　　　　　　　　　　2005-01-20

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