I have an FT-847 with the good internal preamps. The ARR SP432VDG even makes this setup BETTER! I use both the internal and SP-432VDG. Signals are mostly VERY good. Also use a 20 element beam on the downlink.
When I say VERY good, I mean over S9 a lot of the time and all over the place between zero and 60 over 9. That way, you don't have to be so careful in aiming the antenna, and you can hear the birds basically 100% of the time.
If the signal goes down a few S-units you can move the antenna and get it
back up again. Without all that, when it goes down a few S-units, it's GONE!
Regarding the power cable, I have been using two of these preamps for years and years with a small cable attached and no problems.
73 John K6YK
On Mon, 31 Mar 2008 14:03:10 -0500 "Alan" ve4yz@mts.net writes:
Very timely discussion for me as the snow sloooowwly disappears and the return of the Canada geese and robins signals the time for tower work :-)
Some previous comments suggest that a preamp near the rig is not significant, but, I suggest otherwise as my Ft-847 internal preamps can make a significant difference in RX. Anecdotal, not empirical, but I can hear the diff at the push of a button.
Now, I am consider mast mounted preamps as an alternative to my FT-847 internal preamps for one of my sites. I run Landwehr VHF and UHF preamps at 2 other locations and they are terrific! They are also almost 20 years old and no longer available :-(
The preamps on the AR2 site look like what I could use.
My questions are... Is the sequencer
http://www.advancedreceiver.com/page20.html
really necessary or recommended when using the MSP432VD-25 or MSP144VDG-25 preamps? My first thought is NO. 15-20 years of use of 4 Landwehr preamps without a sequencer is my rational.
Finally, does anyone have a nice "warranty voiding" hack to get around the these different power connectors we see on indoor preamps and down converters such as my KEPS http://www.keps.it/images/13lnc72db_m.jpg ? Instead of soldering to the pin and a ground lug
http://picasaweb.google.com/ve4yz.alan/24Ghz/photo#5172119570416133618
Something as simple as removing the connector from the case and running a cable through the remaining hole, soldered internally with something like Anderson Power Poles at the other end for 12VDC????? I'm going to do it one day, but would rather have someone else confirm that it would work without adversely effecting performance characteristics. No guts; no glory here.
Thanks for any feedback
73, Alan VE4YZ EN19kw AMSAT LM 2352 http://www.mts.net/~ve4wsc/ AMSAT A-485
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
On Mar 31, 2008, at 2:11 PM, John W Lee wrote:
I have an FT-847 with the good internal preamps. The ARR SP432VDG even makes this setup BETTER! I use both the internal and SP-432VDG. Signals are mostly VERY good. Also use a 20 element beam on the downlink.
For those interested, there was a nice discussion of how to calculate the noise figure of cascaded pre-amps on the Repeater-Builder mailing list about two weeks ago.
The postings should be pretty easy to find in the RB list's archives at YahooGroups.
If you're not interested in Repeaters, you can always join a YahooGroup (if the list is on YahooGroups) and set your preferences to "no e-mail", so you can read list archives, look in the Files area, etc.
-- Nate Duehr, WY0X nate@natetech.com
At 12:29 PM 4/2/2008, Nate Duehr wrote:
On Mar 31, 2008, at 2:11 PM, John W Lee wrote:
I have an FT-847 with the good internal preamps. The ARR SP432VDG even makes this setup BETTER! I use both the internal and SP-432VDG. Signals are mostly VERY good. Also use a 20 element beam on the downlink.
For those interested, there was a nice discussion of how to calculate the noise figure of cascaded pre-amps on the Repeater-Builder mailing list about two weeks ago.
The postings should be pretty easy to find in the RB list's archives at YahooGroups.
If you're not interested in Repeaters, you can always join a YahooGroup (if the list is on YahooGroups) and set your preferences to "no e-mail", so you can read list archives, look in the Files area, etc.
-- Nate Duehr, WY0X nate@natetech.com
OR...you can click on this link to my website for a spreadsheet that calculates noise figure, noise temperature, and MDS for three cascaded stages. The whole spreadsheet which will calculate eme path-link performance for two stations. But the first section deals with calculating noise figure.
http://www.kl7uw.com/emelink.xls
***************************************************** 73, Ed - KL7UW BP40iq, 6m - 3cm 144-EME: FT-847, mgf-1801, 4x-xp20, 185w http://www.kl7uw.com AK VHF-Up Group NA Rep. for DUBUS: dubususa@hotmail.com *****************************************************
Edward Cole wrote:
OR...you can click on this link to my website for a spreadsheet that calculates noise figure, noise temperature, and MDS for three cascaded stages. The whole spreadsheet which will calculate eme path-link performance for two stations. But the first section deals with calculating noise figure.
Nice work! :-)
Nate WY0X
participants (3)
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Edward Cole -
John W Lee -
Nate Duehr