On Sun, 14 Aug 2022 00:19:53 -0700 (PDT), "John Miles, KE5FX"
<jmiles@gmail.com> wrote:

>On Saturday, August 13, 2022 at 11:04:08 PM UTC-7, Mike Monett wrote:
>> I'm interested. Can you name some of the best and who sells them? 
>
>LMX2820 (TI) and 8V97003 (Renesas) are two of the best integrated
>PLL/VCO parts I've seen.  The LMX2595 has similar specs but the 
>LMX2820 has some nice advantages, such as lower flicker noise and 
>the ability to drive both phase detector inputs externally.
>
>Look them up on octopart.com and you'll see that they are all 
>sitting in Chinese warehouses by the tens of thousands, waiting for 
>buyers who don't mind paying 4x-5x MSRP.  
>
>ADF4371 (62.5 MHz - 32 GHz) also looks good.  Some stock left at
>Mouser.   
>
>Of all these parts, I've only messed with the LMX2820 in person.
>I have a demo board for the Renesas part but haven't gotten
>around to powering it up and trying it out yet.
>
>-- john, KE5FX

We use the LMX2571 as the internal trigger generator in one product.
Jitter is great. It was a huge pain to program, as TI doesn't reveal
the code that they use in the demo kit. Everybody has to figure it out
for themselves. The data sheet is 62 pages long and the app note is
another 31.

We have to suspend triggers while reprogramming the synth, which some
users don't like.

Gerhard Hoffmann <dk4xp@arcor.de> wrote:

[...]

 
> If someone wants to play with these things, there are enough
> boards. Hot air soldering is required, minimum.
> 
> cheers,
> Gerhard   DK4XP
 
Very interesting. Thanks

Mike VE3BTI 
 



-- 
MRM

"John Miles, KE5FX" <jmiles@gmail.com> wrote:

> On Saturday, August 13, 2022 at 11:04:08 PM UTC-7, Mike Monett wrote:
>> I'm interested. Can you name some of the best and who sells them? 
> 
> LMX2820 (TI) and 8V97003 (Renesas) are two of the best integrated
> PLL/VCO parts I've seen.  The LMX2595 has similar specs but the 
> LMX2820 has some nice advantages, such as lower flicker noise and 
> the ability to drive both phase detector inputs externally.
> 
> Look them up on octopart.com and you'll see that they are all 
> sitting in Chinese warehouses by the tens of thousands, waiting for 
> buyers who don't mind paying 4x-5x MSRP.  
> 
> ADF4371 (62.5 MHz - 32 GHz) also looks good.  Some stock left at
> Mouser.   
> 
> Of all these parts, I've only messed with the LMX2820 in person.
> I have a demo board for the Renesas part but haven't gotten
> around to powering it up and trying it out yet.
> 
> -- john, KE5FX

Very good info. Thanks



-- 
MRM

Am 14.08.22 um 09:19 schrieb John Miles, KE5FX:
> On Saturday, August 13, 2022 at 11:04:08 PM UTC-7, Mike Monett wrote:
>> I'm interested. Can you name some of the best and who sells them?
> 
> LMX2820 (TI) and 8V97003 (Renesas) are two of the best integrated
> PLL/VCO parts I've seen.  The LMX2595 has similar specs but the
> LMX2820 has some nice advantages, such as lower flicker noise and
> the ability to drive both phase detector inputs externally.


I have published a synthesizer based on LMX2594 (15 GHz) in
Dubus 1/22. I will put it on my web site sooner or later, but
the chip is currently vapourware.
< 
https://www.flickr.com/photos/137684711@N07/51691780129/in/datetaken/    >

< 
https://www.flickr.com/photos/137684711@N07/51519856398/in/dateposted-public/ 
     >

There is 1 hittite HMC-451 output amplifier populated to drive
a HMC-220 ring mixer. The TI dongle & software cannot tell
it from an eval board.


There will be a companion clock generator with either a
100 MHz crystal oven or a CVHD-950. The oven/VCXO can be locked
to an external 10 MHz reference. It delivers
300 MHz for LMX2594 in fractional mode or
400 MHz for LMX2594 in integer mode.

400 MHz uses 2 SAW filters after the multiplier,
300 MHz uses 2*3pole LC, top coupled.
I could not find a nice 300 MHz SAW filter that is not EOL
or has less than 10 dB loss.

A previous version had some 10 MHz spurious from
the 1/10 prescaler.  It also had only 300 MHz.

< 
https://www.flickr.com/photos/137684711@N07/52284841519/in/dateposted-public/lightbox/ 
    >

It could be used for a DDS also, but currently there is no
need to rush it because of the 2594.


> Look them up on octopart.com and you'll see that they are all
> sitting in Chinese warehouses by the tens of thousands, waiting for
> buyers who don't mind paying 4x-5x MSRP.
> 
> ADF4371 (62.5 MHz - 32 GHz) also looks good.  Some stock left at
> Mouser.

At least it has some filtering after the output doubler.
The ADF5356 had a subharmonic that was horrible.

< 
https://www.flickr.com/photos/137684711@N07/50403778976/in/dateposted-public/ 
    >

If someone wants to play with these things, there are enough
boards. Hot air soldering is required, minimum.

cheers,
Gerhard   DK4XP

On Saturday, August 13, 2022 at 11:04:08 PM UTC-7, Mike Monett wrote:
> I'm interested. Can you name some of the best and who sells them? 

LMX2820 (TI) and 8V97003 (Renesas) are two of the best integrated
PLL/VCO parts I've seen.  The LMX2595 has similar specs but the 
LMX2820 has some nice advantages, such as lower flicker noise and 
the ability to drive both phase detector inputs externally.

Look them up on octopart.com and you'll see that they are all 
sitting in Chinese warehouses by the tens of thousands, waiting for 
buyers who don't mind paying 4x-5x MSRP.  

ADF4371 (62.5 MHz - 32 GHz) also looks good.  Some stock left at
Mouser.   

Of all these parts, I've only messed with the LMX2820 in person.
I have a demo board for the Renesas part but haven't gotten
around to powering it up and trying it out yet.

-- john, KE5FX

"John Miles, KE5FX" <jmiles@gmail.com> wrote:

> On Saturday, August 13, 2022 at 9:24:21 PM UTC-7, Mike Monett wrote:
>> I am absolutely amazed by the quantity and quality of your
>> documentation. This would take a normal human a year to complete. 
> 
> Thanks!  There was lots of room for improvement (the crystal filter/
> comparator section is just embarrassing) but it performed well 
> on a $/dBc/Hz basis.  And it did made a very nice article for QEX.
> 
> Nowadays, all that stuff fits on a single IC and provides 20 GHz of
> coverage with far less noise of both white and flicker varieties.  Of 
> course the best chips are unobtainium TI parts that have to be sourced 
> from Chinese scalpers at prices well into the 3-digit range, but that
> seems to be the new way of the world. 
> 
> -- john, KE5FX

I'm interested. Can you name some of the best and who sells them?




-- 
MRM

On Saturday, August 13, 2022 at 9:24:21 PM UTC-7, Mike Monett wrote:
> I am absolutely amazed by the quantity and quality of your documentation. 
> This would take a normal human a year to complete. 

Thanks!  There was lots of room for improvement (the crystal filter/
comparator section is just embarrassing) but it performed well 
on a $/dBc/Hz basis.  And it did made a very nice article for QEX.

Nowadays, all that stuff fits on a single IC and provides 20 GHz of
coverage with far less noise of both white and flicker varieties.  Of 
course the best chips are unobtainium TI parts that have to be sourced 
from Chinese scalpers at prices well into the 3-digit range, but that seems 
to be the new way of the world. 

-- john, KE5FX

"John Miles, KE5FX" <jmiles@gmail.com> wrote:

> On Saturday, August 13, 2022 at 8:18:00 PM UTC-7, Mike Monett wrote:
>> Amazing documentation. Thanks. 
> 
> Pretty awful synthesizer design, though. :)
> 
> -- john, KE5FX

The performance is clearly superior to the ICOM. Congratulations.

I am absolutely amazed by the quantity and quality of your documentation. 
This would take a normal human a year to complete.



-- 
MRM

On Saturday, August 13, 2022 at 8:18:00 PM UTC-7, Mike Monett wrote:
> Amazing documentation. Thanks. 

Pretty awful synthesizer design, though. :)

-- john, KE5FX

"John Miles, KE5FX" <jmiles@gmail.com> wrote:

> On Friday, August 12, 2022 at 9:08:27 AM UTC-7, Mike Monett wrote:
>> A New Frequency Synthesis Technique 
>> . . .
>> The description of Rational Approximation Synthesis starts on page 151. A 
>> block diagram is on page 156. 
> 
> Amusing.  That wasn't exactly 'new' when I implemented it in 2002 or so.
> ( http://www.ke5fx.com/synth.html )  It was probably still covered
> by one Qualcomm patent or another at the time, in retrospect.
> 
> I used a crystal filter rather than a narrowband VCXO, but same difference.
> 
> -- john, KE5FX

Amazing documentation. Thanks.

Mike 



-- 
MRM