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I was thinking the cheap Chinese chips might be counterfeits also and not meeting specifications of the actual AD chips.?

Based on eBay policy... I think these can be refunded and not have to be returned also.?

I was wondering about the board design too and wondering if needed to can in more a stripline or microstrip type enclosed design or technically... if I understand correctly use multilayer PCB designs and similar theory to spec the board more critically... versus just dual layer.

Is there something going on with the black board versus green board designs in general or more a board design performance for each module... I'm probably trying to over generalize?

There are some ADF5801 modules on ebay that look interresting.
I bought one.
The performance is, after replacing the output pull up inductors not very bad with an IF between 200MHz and 400MHz but conversion loss is -20dB at 2GHz and also bad at 10.7MHz because of the output balun.
I will try to replace the output balun and test some more

I bought some chinese modules from ebay.
Most had wrong components or bad layout and did not deliver the promised performance
Normally? they copy some sw, copy the hw reference design with some cost reductions and build something.
Example is an adf4351 module.
To get the promised performance you have to use three ultra low noise 3.3v? regulators, one for only the vco. The chinese design uses one normal regulator and some inductor capacitor combination to try to remove crosstalk. That failed and as a result the module has terrible spurs and is not usable.
If you are spending that money better buy known brand from solid seller.

Not sure who you are asking.
My sw is also on windows using .net.

I'd be interested in the RPi software you are using. Much of what others have done seems to be Windows based. Or are you using Wine?

Thanks,

Dave L.

Hi,?

There has been some discussion regarding the March edition of the RF and Microwave Source by AD that notes the ADF4371 which looks really impressive though the chip is about as much as the LMX2594/LMX2595.

?

The ADF4371 will be interesting to see developed onto a more cost effective PCB module and sold more affordably.?

?

If you haven't seen like the ADF4355 or like the LMX2594 you noted already more-so cost effectively modularized yet.? Seems compared to the eval board... there still is potential for a nice profit margin product.?

There is also the following that caught my attention and I commented somewhere in another post:

LMX2595:

ADF5355:


I haven't read into the performance characteristics yet.??

?

Kindest Regards,?

?

In Christ.

Hi,

maybe not exactly home brewed test equipment but it might be useful anyway...
Anyone tested this type of RF signal generator?

Cannot find anyone who have tested it. The closest I get is the which is 4 times the price.

Cheers
Marcus, SA5PMG

The log detector of the SI is good but the ability to see a small signal close to a big signal is to be investigated. According to the data sheet at least.
I ordered one to test.

Thank you for the interdigital filter link.

On the same site you can also find a very interesting 199MHz Spectrum Analyzer design (As an alternative to Specan). Especially the use of a SI4432.as IF and log-detector.

73 de oz9ny niels

On Mon, Mar 11, 2019 at 05:54 AM, Marcus Gustafsson wrote:

what about pipe cap filters?

Reminds me of this design of Cavity Filter that almost looks like a combination of the Interdigital Filter and Pipe Cap Filter (coupling difference only looks like):

?(see link below for more details, this is the SA link)

Here is the home link:?

For the rest of the box, a couple mm here or there does not matter as
much. It is only the resonator length that is critical.
If the box sizes are far out, you may end up with a filter that has a
different input impedance (tho that is related to tuning of the filter
as well) or needs long screws to be in tune.

Err on the larger side for the box, and shorter side for the
resonators, and it should be possible to tune the filter.

73 de Thomas.

man. 11. mar. 2019 kl. 09:40 skrev <erik@...>:

Thomas,

That is indeed the calculation I used.
The height of the interdigital filter is calculated a 1/4 labda. How critical is this? Its not easy to make a very accurate box.
If only the rod length is really critical I may try to build one.

--
With Best regards, Thomas S. Knutsen.

Please avoid sending me Word or PowerPoint attachments.

In my opinion, pipe cap filters are best suited above 3GHz. I have
used them up to 24GHz without problems, but their size compared to
bandwith and loss makes them little suitable below approx 3GHz. Just
as I would not build a Interdigital filter for frequencies below
400MHz, below that regular LC filters work quite fine if built
correctly.

73 de Thomas.

Den man. 11. mar. 2019 kl. 13:54 skrev Marcus Gustafsson
<mankan@...>:

--
With Best regards, Thomas S. Knutsen.

Please avoid sending me Word or PowerPoint attachments.

Hi all,

So you found the perfect mixer and want to test it, should you try to find a PCB or do a quick prototype?
Using a small bare PCB, three short wires, three SMA edge connectors and some paper is sufficient.


The SMA connectors are shifted on the edge of PCB (I re-used a PCB) with copper on top, center pins isolated with small slices of normal paper cut to fit between the ground pins and long enough to extend underneath the mixer pins.
The mixer is soldered onto the PCB with pins 1,4 (actually not connected on this mixer) and 5.?
Short wires connect the SMA center pins to pins 2,3 and 6.
Paper will not burn if you solder below 280 degrees Celsius and its a very good dielectric.
The short wires can act as micro strip line with about 50 ohm impedance of you keep them low on the paper.
You can check using calculator
This mixer on PCB is happy to mix till at least 4GHz

Thomas,

That is indeed the calculation I used.
The height of the interdigital filter is calculated a 1/4 labda. How critical is this? Its not easy to make a very accurate box.
If only the rod length is really critical I may try to build one.

I would suggest skipping the cavity, and building a interdigital
filter:

Altough the link shows it as some nice, milled aluminium boxes, you
can make them by soldering pices of brass sheet or even unetched PCB
together. Brass tubing and screws from a model shop, and brass sheet
or PCB and you should be able to make a decent filter at a low cost.

The only thing that is somewhat critical is the length of the
resonator. Try to get this to 0.1mm, but err on the short side. You
can always compensate a bit with the tuning screws if the resonators
are a bit too short, but not if they are too long.

Interdigital filters should be the workhorse of homebrew UHF (sub 3GHz) filters.

73 de Thomas LA3PNA.

s?n. 10. mar. 2019 kl. 21:05 skrev <niels@...>:

--
With Best regards, Thomas S. Knutsen.

Please avoid sending me Word or PowerPoint attachments.

2 of the 3 sim-83+ mixers on sma board i bought from a reputable vendor where bad at arrival. Not sure want to buy these again.?
I would go for ADE-42MH as first mixer an ADE-25MH as second and third. These are level 13 mixers giving a bit better isolation and IP3 at a bit higher price
For best performance you want to use level 23 mixers or even better but at 100$ a piece on a pcb that is to much for me. And then I even ignore the LO amplifier you need to drive them.

Forgot to mention. Do not drink strong coffee before manually soldering 0603 components

On Sun, Mar 10, 2019 at 01:42 AM, <erik@...> wrote:

And +6 glasses

Never thought of... do I feel like a newbie.? Looks like there are cost effective Jewelers Loupe glasses and the optivisor or headband magnifiers.??

?

I see??has an interesting selection also for smaller component PCB's and components... though I haven't read into those specifications.?

Were you using the??for the SIM series?? ?The gentleman noted he had a?SIM-83+ mixer in stock and he doesn't put the SIM-153+ on a board because the connectors he uses will not support frequencies that high.

I was wondering what R&S use in their Spectrum Analyzers with the low noise floor claimed in the -160dB's.?

I? found 2.4GHz SAW filters at mouser. Bought some and tried to put one on a pcb. That failed, but will try again
eBay has 1.090GHz filters with SMA connectors that shoul work.
1GHz is much easier than 2.6GHz and the only reason I try 2.6GHz is to make use of the ADF4351 rang.
I may also build a 2.18GHz interdigital filter myself. The calculations are ready.
Using 2.18GH will allow using a direct conversion to I/Q baseband on 192kHz samplerate audio. Not sure mirror surpression will be good enough when doing audio fft for very small RBW