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KIT LPF


bernard BREYNE
 

 

Hello everyone, someone would have made it the different LPF kit. I can't find a good result on the response curves with the Nanovna. The central frequency is sometimes very far from the central frequency of the band.  Is there anyone who can help me? F1IEO


geoff M0ORE
 

LPF or BPF, a LPF doesn't have a central frequency.

On 11/07/2020 09:13, bernard BREYNE wrote:

 

Hello everyone, someone would have made it the different LPF kit. I can't find a good result on the response curves with the Nanovna. The central frequency is sometimes very far from the central frequency of the band.  Is there anyone who can help me? F1IEO


Bob Benedict, KD8CGH
 

Bernard - with nanosaver on your PC you can capture and then post the trace which will help diagnose the problem.
--
  73
    KD8CGH


tk5ep
 

Bonjour,
un filtre passe-bas n'a pas de fréquence centrale mais une fréquence de coupure. N'y a t-il pas confusion ?

Postez une image de votre mesure.

73 EP


bernard BREYNE
 

Hello, thanks for the answers. I'll attach you some pictures of the images of the Nanovna. I should point out that the filters are installed on the LPF kit with the relays. Thank you in advance. 73 QRO
  F1IEO

Le sam. 11 juil. 2020 à 15:30, tk5ep <pegloff@...> a écrit :

Bonjour,
un filtre passe-bas n'a pas de fréquence centrale mais une fréquence de coupure. N'y a t-il pas confusion ?

Postez une image de votre mesure.

73 EP


Bob Benedict, KD8CGH
 

How did you calibrate the NanoVNA? These don't look low low pass filters. Are you sure they are plugged in correctly (in vs out)?
If you search the posts you can find that I and others built a simple filter holder for the filter and calibrated that holder.
Here is my sweep of my 30 m low pass filter



--
  73
    KD8CGH


Ronald Taylor
 

Bernard, you mentioned you are using the lowpass filter relay board. Did you put the highest frequency filter in the number one slot as required? If not, did you install the proper jumpers to to bypass that requirement? Can you check the filter in question without it being installed on the relay board to see if you get different results? ... Ron


bernard BREYNE
 

Hello Ronald, thanks for the answer. Yes I installed the filter larger frequency in 1. The straps are properly installed. I do not have the turntables to test the LPF separately. I don't know if we can still buy them. 73 


bernard BREYNE
 

Hello, I can not see your image, too clear. The calibration was done but as indicated on the VNA notice. Control by the abacusSmith's is correct. Can tell me how to control my LPF properly. Thank you very much. I respected the number of spires as well as the abilities.???


Bob Benedict, KD8CGH
 

Bernard
  There is a pic of the filter holder I made here  https://groups.io/g/QRPLabs/message/49787
and another one here  https://groups.io/g/QRPLabs/message/49673

I attached the holder to the nanoVNA and then ran the calibrations on the holder. I left the holder empty and ran "open", plugged a wire in from the signal to ground on the CH0 side and ran "short", plugged a 50 ohm resister in across signal and ground and ran "load", left the resister in and ran "isolation" and finally removed the resister and ran two wires from Ch0 to CH1 sides at signal and ground to calibrate "through".

--
  73
    KD8CGH


J P Watters <kc9kko@...>
 

Bernard and Bob,

I stumbled across a ham that created a circuit board that mates with the NanoVNA, I put male connectors on it an attached it directly to the NanoVNA.
No Cables, And easy to calibrate with the on board jumpers. 

https://www.ph2lb.nl/blog/index.php?page=for-sale-qrp-labs-filter-adapter-pcb-v2-for-nanovna-parts

Soldered 4 100 ohm SMD resistors, a couple of 4 position female headers and half a dozen 2 position male headers.

If you want to attached the adapter with cables, solder on a couple female SMA PCB coax edge connectors
or use male connectors to attach it directly to the NanoVNA.

After years of using calibrated open, shorts and loads for calibrating my VNA analyzer, I liked the idea of using
computer 2 position header shorting jumpers to do the calibration. Eliminates the cable swapping.
It makes it as almost as easy as some of the auto calibrate VNA's.

..jpw J P Watters
KC9KKO



J P Watters <kc9kko@...>
 

I forgot to attach a photo to show how nicely it attaches to the NanoVNA.


bernard BREYNE
 

Hello thank you very much for the information. I would love to order a turntable to test the LPF filters like you. What address or email can I order this from? thank you F1IEO I do not understand well the previous order info.

Le lun. 13 juil. 2020 à 09:19, J P Watters via groups.io <kc9kko=mac.com@groups.io> a écrit :

I forgot to attach a photo to show how nicely it attaches to the NanoVNA.


Bob Benedict, KD8CGH
 

Thanks - Nice!
I like having the calibration on the test fixture. That's much more convenient, and probably more consistent, than they way I calibrate my homemade fixture.
--
  73
    KD8CGH


bernard BREYNE
 

Bonjour cher OM , merci pour la réponse. Effectivement je me suis mal exprimé. Mes courbes de réponses me semble pas bonnes. Je vous envoie quelques photos. A moins que ne ne branche pas correctement le filtre ou que les paramètres du Nanovna ne sont pas bon ? seul le 80 m me semble correct.
Merci pour votre aide. 73 F1IEO


Bob Benedict, KD8CGH
 

Bernard
  Did you make a filter holder and calibrate at that holder? 
--
  73
    KD8CGH


bernard BREYNE
 

Good evening, as already said, I have no filter door. I'd like to buy one. I'd like an email address to order it. Thank you.

Le lun. 13 juil. 2020 à 15:34, Bob Benedict, KD8CGH <rkayakr@...> a écrit :
Bernard
  Did you make a filter holder and calibrate at that holder? 
--
  73
    KD8CGH


Bob Benedict, KD8CGH
 

Bernard
  The J P Waters post above has a link. To buy one you email Lex, PH2LB as stated on that page.
Click on the link - "Use contact form if your interested." to get his email address.
--
  73
    KD8CGH


bernard BREYNE
 

Thank you I just ordered from the ex. Thank you.


Le mar. 14 juil. 2020 à 11:47, Bob Benedict, KD8CGH <rkayakr@...> a écrit :
Bernard
  The J P Waters post above has a link. To buy one you email Lex, PH2LB as stated on that page.
Click on the link - "Use contact form if your interested." to get his email address.
--
  73
    KD8CGH