This is a webpage for the ELNA70CM-22N. This is a Extremely Low Noise Preamp for 432 MHz weak signal operation. This product is for the serious Ham Radio Operator who is looking to hear extremely weak signals, such as EME, terrestrial and satellite communications. Without going to the trouble of cryogenics, this type of preamp has the lowest noise figure available at this time. Signal-to-noise improvements of 6 to 14 dB can be expected even with current high end radios such as the Kenwood TS-2000 or the Yaesu FT-847. I have heard clearly echoes off the moon using one FO-22 yagi and this preamp attached directly at the antenna feed point! This preamp is designed around a device that uses E-PHEMT, Enhancement mode Pseudomorphic High Electron Mobility Transistor. The E-PHEMT I design around is very similar to the ATF-54143 except instead of having a NF min of 0.15 it has a NF min of 0.076 dB at 500 MHz! This low NF min along with a very HI-Q Silver plated inductor and HI-Q low loss capacitor is how NF of ~ 0.25 dB can be achieved. Every unit, before being shipped has to measure under 0.3 dB Noise Figure on a HP8970 Noise Figure Meter. The ELNA70CM-22N sells for $125.00 free shipping in the US and only a $20.00 shipping and handling charge in most places outside the US. 1 year warranty. I now have payments via PayPal available.
PayPal Acceptance Mark
Now accepting PayPal

eham.net Review of the ELNA

Heelweg Preamp Test Results 2015





Operating Voltage : 9 to 18 volts DC, Nominal 12 VDC

Current Draw : 65 to 75 mA

Maximum input power without damage : 25 mW

Operating Temperature : -40 to +140 degrees F (-40 to +60C)

Gain @ 432 MHz : Nominal 21.5 dB (see actual measured gain on back of preamp)

NF @ 432 MHz : Below 0.3 dB tested at 75 degrees F (24C) (see actual NF measured on back of preamp)

S1-1 @ 432 MHz : -12 dB Typical (See Graph)

S2-2 @ 432 MHz : -16 dB Typical (See Graph)

1 dB compression : 20 dBm

3rd order intercept : 30 dBm

Mechanical size: 1.9" x 1.9" x 1.22"

Mechanical enclosure material : cast aluminum

Connectors : High quality N-type female, gold plated center

Weight : 5 oz. (~ 142 grams)

Typical Pass Band Response

Typical Input Match

Typical Output Match

Noise Floor/ Window

Noise Figure Min. Chart on active EPHEMT Device

EME Requires Maintenance In All Kinds Of Weather

Current picture of the EME Array in it's parked position with the copper roof of house in the background.

This is a picture of my RX-7 taken in 1992.

My wife Tatyana and Josh in front of the small vertical array