Masters Communications Enclosed Helical Preamps

Custom Products from Masters Communications

EHP-Series - Low-Noise High Dynamic Range
Enclosed Helical Resonator Filtered RF Preamplifiers
for receive applications and duplex (repeater) service.
$155.00 built, tested, tuned - any available connector choice - shipping extra.
$14.50 USPS Priority Insured Shipping in the US.
Shipping on foreign orders are quoted by destination.

Currently available only in UHF.
420-470 MHz -- Ham - Commercial - GMRS.
Other bands under development.

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Masters Communications EHP-Series Preamps - Standard Features:
These standard features are included in all EHP-Series Preamp Products.

Low-loss 2-Section helical resonator input filter.
Low Noise ~ 2dB noise figure - typically 1.8dB.
High dynamic range - based on our EPGA103+ preamp circuitry.
100% totally shielded aluminum box - properly machined for rugged / stable opertion.
12VDC operation at moderate current draw (7-15V acceptable - about 100mA).
P1dB = +14 dBm at the output connector +20dBm at the device - because of output attenuator.
Available with BNC, UHF, or N Female connectors (or a unique combination of any two - can eliminate adapters)
Moderate Gain - Less chance of receiver overload.
These preamps are NOT available as unassembled project kits - comes ready to install.
Power connection is made on the outside via DC Feedthru and ground lug (soldering preferred).
24" Siamese Black/Red power wire supplied - longer lenghts available, small fee applies.
$155.00 assembled, tested, & tuned - with any connector option (BNC, UHF, N - any two).
Built to order and professionally tuned on a HP 8753ES Vector Network Analyzer.
Great input match so your duplexer notch tuning is not pulled out of whack.
Comes with performance graphs showing gain and input return loss (match) on your receive frequency.
Email Kevin to get one built for your repeater.

Individual Features and Model Comparison:

Click on a model number for more information and ordering via email link.

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Frequency Range 420-470 MHz

Application Ham, Commercial or GMRS

Gain in dB (nominal +/- 1dB) 13-14 dB typical

Noise Figure in dB 2.0 dB

Input Return Loss >20 dB

Output Return Loss >20 dB

Overload Point 0 dBm

P1dB +14 dBm at output connector

Bandwidth in MHz. (-3dB) 25

DC Power Requirement 12VDC @ 60 - 100mA

Available RF Connectors
(any combination of two) BNC Female
UHF (SO239) Female
Type N Female

More Information:
Email Kevin Custer for ordering information and/or support of these exciting products.

Products of Masters Communications, all rights reserved.
Specifications may change without notice.
Images are property of Kevin Custer - W3KKC.
Board layout by Kevin Custer - W3KKC.
HTML July 12, 2024, W3KKC All Rights Reserved!

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Frequency Range	420-470 MHz
Application	Ham, Commercial or GMRS
Gain in dB (nominal +/- 1dB)	13-14 dB typical
Noise Figure in dB	2.0 dB
Input Return Loss	>20 dB
Output Return Loss	>20 dB
Overload Point	0 dBm
P1dB	+14 dBm at output connector
Bandwidth in MHz. (-3dB)	25
DC Power Requirement	12VDC @ 60 - 100mA
Available RF Connectors (any combination of two)	BNC Female UHF (SO239) Female Type N Female