[R-390] Distribution Amplifier

Wed, 21 Apr 2004 10:40:16 -0400

Greetings,

Yes, I agree, I'm sure that is why the developer designed the pass filter
to cut of above 75MHz.  I won't change the filter values to allow for the
150 MHz cutoff as I'm sure that the R390A and SP600-JX would be confused by
high power paging signals.  I haven't given up on the valves yet.  I've
just not been lucky enough to find a dist. amp. here at the New England
flea markets.

John Flood
TASC Department
KROHNE, Inc
7 Dearborn Rd.
Peabody, MA   01960
Tel.:  978-535-6060 / 800-356-9464
Fax:   978-535-8180

                      Bob Camp                                                                                                         
                      <[email protected]>               To:      "Scott, Barry (Clyde B)" <[email protected]>                                    
                      Sent by:                 cc:      [email protected]                                                          
                      r-390-admin@mail         Subject: Re: [R-390] Distribution Amplifier                                             
                      man.qth.net                                                                                                      

                      04/20/2004 09:50                                                                                                 
                      PM                                                                                                               

Hi

Well don't throw out all the glow in the dark stuff quite yet .....

The video amplifiers that form the heart of the ARRL project are pretty
darn nice little chips. However they are not rated for IMD and their
harmonic distortion numbers begin to climb as you go past about 10 or
12 MHz. That isn't to say they fall apart. Far from it they probably
work pretty darn well considering what they are.

What they are not is the tuned RF front end on an R-390. I would be
very interested to see how they do when attached to a couple hundred
feet of wire with the bands open ...

             Take Care!

                         Bob Camp
                         KB8TQ

On Apr 20, 2004, at 1:04 PM, Scott, Barry (Clyde B) wrote:

> Looks like a really well-designed project; however, I'm afraid if I
> built
> it, I'd start looking for 6 more receivers...
>
> Barry(III) - N4BUQ
>
>
>> Hi, Pete, and ALL,
>>
>> The author and designer of the multicontroller has a neat web
>> site that
>> describes the project pretty well.  Go to:
>>
>>           www.w8zr.net/multicontroller/
>>
>> In speed reading the QST article just now, I did not see a
>> noise floor
>> specification mentioned, but he is using new Maxim MAX497CPE
>> video amplifier ICs
>> each containing four 275 Mhz low-noise amplifier/buffers.
>>
>> I, too, am very interested in getting his kit and building it
>> for all my receivers.
>>
>> Marshall Dues  WB5MYO
>> Katy, TX
> _______________________________________________
> R-390 mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/r-390
>

_______________________________________________
R-390 mailing list
[email protected]
http://mailman.qth.net/mailman/listinfo/r-390