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Reviews Categories | Receive Pre-amps | RAMSEY PR40 440mhz preamp Help


Reviews Summary for RAMSEY PR40 440mhz preamp
RAMSEY PR40 440mhz preamp Reviews: 6 Average rating: 4.8/5 MSRP: $14.95
Description: 440 MHZ low noise preamp kit
Product is in production.
More info: http://www.ramseykits.com
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K3MD Rating: 5/5 Sep 8, 2010 07:42 Send this review to a friend
Very good  Time owned: 0 to 3 months
Purchased and assembled this unit and combined with a Fair Radio Sales FAA type N relay and a homebrew relay-type sequencer, with 35 volts for relay being provided by a half-wave doubler from 12 v ac. Power to preamp provided by 12 v voltage reglator from the voltage for the relay.
Works excellent.
Beacon from W3CCX (110 mile distance, 5 watts)jumps up to 10 to 20 dB above noise when unit switched on. Much better than preamp inside shack included in RFconcepts amplifier.
Housed in outside 8 by 8 inch junction box.
What a value for $20! $400 mast-mount preamp/sequencer for $60 total cost!
 
XE1VE3OQC Rating: 5/5 Feb 19, 2010 09:26 Send this review to a friend
Great preamp!!  Time owned: 0 to 3 months
I bought two of these to use on my downlinks on 435 and what a difference these make!
On low passes from HO68 when the beacon was barely audible and then for only 50% of the pass, when I turned on the preamp beacon came from barely audible to S6 for pretty much the whole pass.
For $12 and 10 minutes I saved myself $300 on commercial units.
Nice play Ramsey!!!
 
KF4ZMT Rating: 5/5 Aug 19, 2008 07:58 Send this review to a friend
Outstanding Pre-Amp  Time owned: 0 to 3 months
My 14 year old daughter (who is also a HAM) assembled this kit for me. I use it for making LEO satellite contacts along with an Arrow antenna and Yaesu FT-60R and it works great. I did not find it necessary to bother with the Ramsey RF relay. I am only transmitting 5 watts and the MFJ duplexer I use sufficiently attenuates my 2 meter transmit signal on the 70cm side of the duplexer to avoid damaging the pre-amp. I'm very impressed with this product.
 
WB1AAT Rating: 4/5 Dec 18, 2007 11:34 Send this review to a friend
Very good for what it is  Time owned: 3 to 6 months
I built one of these for use with satellites. It went together easily and a phone question I had for Ramsy went answered quickly and clearly. For 15 bucks its a great deal and I will be using this as a RX booster for my outdoor use using a handheld antenna. Its not a SSB or ARR, but then again, these cost 4-10x more!

I got almost 4 S units improvement overall, but it definately amplifies the noise with the signal too. Put it this way. If you can barely hear it before, you can hear it better with the preamp, but it will still have prominent background hiss. If the signal is moderate, it will make it a strong signal. To my experience, it wont pull an unreadable signal thats in the noise out of the noise. It's just doesnt have a low enough noise figure to do that.

Some lessons learned though:

- it comes with no case, so you need to scrape up a small a shielded box to put it in. Perhaps PVC pipe if mounting outside. I used a small aluminum project box with a 9V battery and a switch.
- any RF into this will smoke the transitor. It only takes one time to pop it and I did it with as little as 1 watt. The transitor is cheap ($1.50) and easy to replace though and a good practice I use on my THF6 is to use the menu to inhibit transmit to prevent recurrences.
- the manual recommends a DPDT switch to switch it in and out of the line. If you want to protect the circuits (isolate both input and output antenna line) as well as switch the power, you need at least a 3PDT switch. This is how I did it.

Ramsey recommends the RFS1 RF Sense kit to prevent popping the preamp. I bought it but havent gotten around to building it. I May not actually.

All in all, a fun, cheap, and small preamp. But definately cant compete with the "big boy" preamps.

 
VE6KJM Rating: 5/5 Jan 18, 2007 15:09 Send this review to a friend
Excellent Unit  Time owned: 6 to 12 months
I built these for use with my homebrew yagi antenna on the LEO Sats, and they make the difference between hearing and not. I have used them on both FM & SSB and they work Great.

When you order them also order the RF detecting Relay as well as it is not WILL it happen but WHEN you key the mike with the preamp in-line and make it smoke. They are well worth the money. My tests shows about 16db signal gain with less that 1db noise gain because of the filtering designed in them. I have 2 sets of antenna, One set for transmitting the other set with Preamps that are used for listening.
 
N8EKT Rating: 5/5 Jul 9, 2005 08:07 Send this review to a friend
FANTASTIC!!  Time owned: 0 to 3 months
This preamp only takes 15 minutes to build.
Performance is fantastic.
Over 20db gain at about 1db noise figure.
I replaced a gasfet repeater preamp with this Ramsey PR40, and the Ramsey performed just as well and is 1/5th the price!
 


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