Nyquist filter coils L1,L3,L2,L4

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M0ATV
Posts: 81
Joined: Fri Aug 13, 2010 6:00 pm

Nyquist filter coils L1,L3,L2,L4

Post by M0ATV » Thu Sep 29, 2011 11:18 am

In regard to Dave G8AJN's post in this section > http://www.batc.org.uk/forum/viewtopic.php?f=71&t=978


Just to add that if anyone finds an alternative source other than RS or Farnell, can they post a location, as minimum cost from RS is £10.69 delivered & Farnell minimum order £20, so if like me you have already ordered all parts from original listing then its a bit steep for a couple of bits. Tony M0ATV


Nyquist filter coils L1,L3 (5.6uH) are RS 191-0453 (Farnell 509-929) and L2,L4 (6.8uH)are RS 191-0469 (Farnell 164-4263).

G0MXW
Posts: 27
Joined: Thu Sep 29, 2011 4:59 pm

Re: Nyquist filter coils L1,L3,L2,L4

Post by G0MXW » Thu Sep 29, 2011 5:10 pm

Tony

Ordered some spares and it looks like I'll have to wait for 2nd batch of pcb's . Yours if you PM me a snail mail address.

Dave

G4EWJ
Posts: 1456
Joined: Wed Feb 17, 2010 10:11 am

Re: Nyquist filter coils L1,L3,L2,L4

Post by G4EWJ » Thu Sep 29, 2011 5:16 pm

JabDog have those values, but it doesn't say much about the spec.

Brian

http://www.jabdog.com/toko-FL.htm

M0ATV
Posts: 81
Joined: Fri Aug 13, 2010 6:00 pm

Re: Nyquist filter coils L1,L3,L2,L4

Post by M0ATV » Thu Sep 29, 2011 9:06 pm

Dave have dropped you a pm, thanks Francois & Brian for info.

G0KTD
Posts: 45
Joined: Wed Jun 08, 2011 7:39 am

Re: Nyquist filter coils L1,L3,L2,L4

Post by G0KTD » Thu Oct 20, 2011 8:48 am

Got Mine of Ebay

Low Current Axial RF Inductor Choke 6.8uH (5 Pack)
Spiratronics Electronic Components
5.6uH Axial Lead Color Ring Fixed Inductor, 5.6 uH http://stores.ebay.co.uk/AudioWind?_trksid=p4340.l2563 these from Kowloon HK
these have not arrived as post is slow.

Keith G0KTD :D

g8ajn
Posts: 45
Joined: Sun Mar 16, 2008 1:59 pm

Re: Nyquist filter coils L1,L3,L2,L4

Post by g8ajn » Sun Oct 23, 2011 11:46 am

The next version (5.7) of the pcb will have an option for smd or radial coils, however it should be remembered that the smd coils have a much poorer Q value than the radial and might give somewhat degraded results.If possible I would suggest that local groups could perhaps put in a combined order for these and other similar parts.
Dave

w0fms
Posts: 23
Joined: Wed Oct 12, 2011 10:46 pm

Re: Nyquist filter coils L1,L3,L2,L4

Post by w0fms » Tue Oct 25, 2011 11:38 pm

I got lucky in that I had a bag of 30 year old (probably) surplus inductors similar to the ones that you used that had several 5.6 uH and 6.8 uH RF chokes in the bag. (They are usually used as chokes).

It might also be possible to wind these on small powdered iron toroid cores.

37 turns on a T-50-6 or a T-37-2 toroid would work for 5.6 uH (-2% approx) for example and probably have decent enough "Q".
41 turns on a T-50-6 or a T-37-2 toroid would work for 6.8 uH (-1% approx).

I would have done this if I had not been able to find the commercial molded parts in my junk box. I suspect it would work fine.

To attach toroids to the board, hot melt glue works dandy.. the turns can and should be encapsulated in the same goop.

Fred W0FMS

on4bhm
Posts: 79
Joined: Mon Oct 24, 2011 5:52 pm

Re: Nyquist filter coils L1,L3,L2,L4

Post by on4bhm » Fri Nov 25, 2011 2:41 pm

Can i buy from someone the items that are te be changed for a 70cm version of digilite?

my next digilite will be one for 70cm... i have all the part ordered twice.
but i forgot that there are other parts needed for a 70cm version.

i can pay with paypal if needed.

thanks
on4bhm (at) telenet.be
73's

G4OHV
Posts: 37
Joined: Sat Oct 08, 2011 10:31 pm

Re: Nyquist filter coils L1,L3,L2,L4

Post by G4OHV » Fri Nov 25, 2011 3:47 pm

Hi

I can supply you with 2 off, 4.7uH, 22uH and 33uH inductances, but not the AD8345 or the 3.9nF caps.

regards

Col

M0DTS
Posts: 684
Joined: Sun Feb 24, 2008 9:03 pm

Re: Nyquist filter coils L1,L3,L2,L4

Post by M0DTS » Sat Nov 26, 2011 8:36 pm

We may have an issue with values being used for 2Ms on 70cm configuration...

If i remember correctly:
2Ms we should be using 560pf/12uH/2n2/15uH/560pf
1Ms it should be 1n2/27uH/3n9/33uH/1n2

Rob
M0DTS

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