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C210 and C216


 

Hi.
?
I'm homebrewing a uBITX to go with the factory model, ultimately trying to add a few things Farhan has suggested. like the HYCAS IF strip.
?
I am trying to breadboard the 45 MHz filter at the moment and have a couple of questions.
?
The first is the value of C210 and C216 in the 45 MHz filter section. As I read the schematics on both V3 and V4 I only see a "0" for the capacitor value.? If anyone can tell me what that should be before I tear into my V3 and try to figure it out I'd be in your debt.
?
Second, I bought a matched pair of the TMCF 45 MHz crystal filters from Ebay.? I breadboarded 1 by itself and it looked pretty good, but since I have the other is it worth trying to build from scratch with the 4 pole filter, and if so, has anyone seen an app sheet for that?? I can find the spec sheet but it doesn't show how the matched pair should be configured. I've seen a few other types of matched pairs that suggest for example that the filters should be in series, with the black dots connected, but nothing more than that.
?
Thanks for any clues or help.
?
Scott ka9p


 

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Both sites are unpopulated on my V3 board.?

Mike

K5ESS

?

From: [email protected] [mailto:[email protected]] On Behalf Of Scott McDonald via Groups.Io
Sent: Friday, December 14, 2018 12:04 PM
To: [email protected]
Subject: [BITX20] C210 and C216

?

Hi.

?

I'm homebrewing a uBITX to go with the factory model, ultimately trying to add a few things Farhan has suggested. like the HYCAS IF strip.

?

I am trying to breadboard the 45 MHz filter at the moment and have a couple of questions.

?

The first is the value of C210 and C216 in the 45 MHz filter section. As I read the schematics on both V3 and V4 I only see a "0" for the capacitor value.? If anyone can tell me what that should be before I tear into my V3 and try to figure it out I'd be in your debt.

?

Second, I bought a matched pair of the TMCF 45 MHz crystal filters from Ebay.? I breadboarded 1 by itself and it looked pretty good, but since I have the other is it worth trying to build from scratch with the 4 pole filter, and if so, has anyone seen an app sheet for that?? I can find the spec sheet but it doesn't show how the matched pair should be configured. I've seen a few other types of matched pairs that suggest for example that the filters should be in series, with the black dots connected, but nothing more than that.

?

Thanks for any clues or help.

?

Scott ka9p


 

Same for on both of my v4 boards;unpopulated,

Evan
AC9TU


 

Thanks Mike, just the answer I was hoping for. Merry Christmas. Scott
?
?

-----Original Message-----
From: K5ESS <k5ess.nothdurft@...>
To: BITX20 <[email protected]>
Sent: Fri, Dec 14, 2018 2:46 pm
Subject: Re: [BITX20] C210 and C216

Both sites are unpopulated on my V3 board.?
Mike
K5ESS
?
From: [email protected] [mailto:[email protected]] On Behalf Of Scott McDonald via Groups.Io
Sent: Friday, December 14, 2018 12:04 PM
To: [email protected]
Subject: [BITX20] C210 and C216
?
Hi.
?
I'm homebrewing a uBITX to go with the factory model, ultimately trying to add a few things Farhan has suggested. like the HYCAS IF strip.
?
I am trying to breadboard the 45 MHz filter at the moment and have a couple of questions.
?
The first is the value of C210 and C216 in the 45 MHz filter section. As I read the schematics on both V3 and V4 I only see a "0" for the capacitor value.? If anyone can tell me what that should be before I tear into my V3 and try to figure it out I'd be in your debt.
?
Second, I bought a matched pair of the TMCF 45 MHz crystal filters from Ebay.? I breadboarded 1 by itself and it looked pretty good, but since I have the other is it worth trying to build from scratch with the 4 pole filter, and if so, has anyone seen an app sheet for that?? I can find the spec sheet but it doesn't show how the matched pair should be configured. I've seen a few other types of matched pairs that suggest for example that the filters should be in series, with the black dots connected, but nothing more than that.
?
Thanks for any clues or help.
?
Scott ka9p


 

¿ªÔÆÌåÓý

Thanks Evan, glad to see it hasn¡¯t changed. 73 Scott


On Dec 14, 2018, at 2:58 PM, Evan Hand <elhandjr@...> wrote:

Same for on both of my v4 boards;unpopulated,

Evan
AC9TU