[Yaesu] 2.8kHz Collins filter for the FT-900 for $50.00???

Tue, 12 Feb 2002 15:12:43 -0800

Thanks for the comments John, I'll add it to my notes.  I think the lower
insertion loss filter helps a little but doesn't really cure the problem.  I
suspect the real problem is the notch filter circuit and the two dual-gate
MOSFETS that follow it.  I'd love to dig into one of these and fix the
problem once and for all.

Stuart
----- Original Message -----
From: "Wilson A. Caselli" <[email protected]>
To: "Yaesu REFLECTOR" <[email protected]>
Sent: Tuesday, February 12, 2002 2:23 PM
Subject: Fw: [Yaesu] 2.8kHz Collins filter for the FT-900 for $50.00???

|
| ----- Original Message -----
| From: "AES" <[email protected]>
| To: "Wilson A. Caselli" <[email protected]>
| Sent: Tuesday, February 12, 2002 3:03 PM
| Subject: Re: [Yaesu] 2.8kHz Collins filter for the FT-900 for $50.00???
|
|
| The filter that he is talking about is the YF115S01.  These are no longer
| available from AES.
|
| *********** REPLY SEPARATOR  ***********
|
| On 2/11/2002 at 8:41 PM Wilson A. Caselli wrote:
|
| >Gents:
| >
| >Can you identify the Yaesu part number of the Collins filter mentioned
| >below?
| >
| >Let me know if you can supply one.
| >
| >Thanks,
| >
| >Wilson A. Caselli, K1MIJ
| >12104 Oakhaven Drive
| >Charlotte, NC 28273-3652
| >
| >(704) 588-2944
| >
| >[email protected]
| >
|
>---------------------------------------------------------------------------
| -
| >----
| >----- Original Message -----
| >From: "John Bolduc" <[email protected]>
| >To: <[email protected]>
| >Sent: Monday, February 11, 2002 7:48 PM
| >Subject: Re: [Yaesu] Re: Pin Diodes FT-990
| >
| >
| >> Stuart
| >>      I made a temporary fix to my 990. Here's what I did..... First of
| all
| >> the hiss is from the 455 stage .. From the Murata 455 filter to the
| >product
| >> detector . The audio amps are very quiet , and are not the problem.
Some
| >rig
| >> have noisy audio amp like the 1000MP,  it uses the old TDA2002
chip(very
| >> common part) & the 990 uses the new TDA2003 much better!!
| >>
| >> Ok back to it... I took out that crappy Murata filter & replaced it
with
| a
| >> Collins 2.8khz This is the same filter the 1000MP uses. And AES had
them
| >on
| >> Closeout for $50.00 . But they're label for the FT-900 . Same filter
| >mounted
| >> on a different board, You don't need the board. Put it in the 990 with
| >patch
| >> cable's.
| >>
| >> The big advantage of this filter other than it's superior to the Murata
| in
| >> every way is ...... It has way less insertion loss so the input into
the
| >> first bipolar transistor is higher , So now you can go to the IF gain
pot
| >> located down stream in the circuit and turn it down. You still have the
| >same
| >> receiver sensitivity but the hiss is lower..... This is the same
| principle
| >> that Inrad use's with the 1000MP mod they sell except the use an active
| >amp
| >> in the 70 meg IF .......And turn the IF gain down in the service menu .
| >> This works well for a simple mod ... But the best way would be to use
FET
| >'s
| >> in the 455 IF They have much less noise. My 940 Kenwood use's those and
| is
| >> Way quieter than the 990.  But would be major surgery ..... I'm happy
| with
| >> this simple update plus the IF shift work's better because of the
Collins
| >> great skirts & the audio is better too , because of less filter ripple
&
| >> overall receiver with is wider .........
| >>
| >> 73's john
| >>
| >>
| >> _______________________________________________
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| >> [email protected]
| >> http://mailman.qth.net/mailman/listinfo/yaesu
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| >>
| >>
| >>
| >
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|
| Thank you for contacting AES. We hope we can assist you in the future.
| 73
| Jeff, N9EDQ
| AES, Milwaukee
| WATTS: 1-800-558-0411
| LOCAL: 1-414-358-0333
| FAX: 1-414-358-3337
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| Current prices are subject to change without further notice.
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