0.4 dB NF HDTV E-PHEMT
LOW NOISE AMPLIFIERS (LNA'S)
TYPE 9255
Mains power supply for types 9254 and 9260 LNA'S
DC output 8V + @ 100 ma.
On/off mains switch with LED indicator.
Very low hum and noise levels.
Fully screened and filtered.
110/120V AC or 220/240V AC versions available.
TYPE 9252
Weatherproof enclosure for all LNA types with
fully sealed cable glands,complete with mast fixing and
internal thermal insulation.
Masthead Amplifiers
It is common practice to use unprotected masthead amplifiers that rely on
weather resistant protective boots pushed on over the connectors to help
prevent water damage to the plugs and sockets. However this is not
completely waterproof and moisture can cause bad connections in
plug/socket assemblies, resulting in intermittent signal and/or increase of
noise and a gradual loss of preamplifier output. This is expensive in time
and money to trace and rectify.
A better approach is to put the amplifier into a fully sealed case which uses
waterproof cable glands.
RESEARCH COMMUNICATIONS LTD
ALL UNITS ARE NOW IN STOCK FOR SAME-DAY DESPATCH
This is a range of very low noise television preamplifiers for long distance
analogue and HDTV reception, especially suitable for fringe areas where
drop-outs or low quality pictures are a problem.
Don't put up with poor reception - get the best available.
CONTACT US: PHONE 01303 862842 (UK), 44 1 303 862842 (OVERSEAS).
EMAIL: sales@researchcomms.com or ellenw@hotmail.co.uk
BAND
UHF
FREQUENCY
EU 470-862 MHz. (CAN 470-800 MHz.)
NOISE FIGURE
0.4 dB.
GAIN
23 dB.
FLATNESS
+/- 1 dB.
MAX. OUTPUT
127 dB microvolts.
MATCHING
Return loss 14 dB.       V.S.W.R. 1.5:1
IMPEDANCE
75 ohms.
CONNECTORS
F sockets.
POWER
+8V. DC @ 73 ma approx.
DIMENSIONS (ins)
L 2 x W 1.5 x H 1.25 ins approx.
DIMENSIONS (mm)
L 52 x W 48 x H 30 mm approx.
CASE
Diecast aluminium.
FINISH
Natural.
FREQUENCY
ATTENUATION
FREQUENCY
ATTENUATION
50 MHz
-80 dB.
600 MHz
0 dB.
100 MHz
-70 dB.
700 MHz
0 dB.
200 MHz
-50 dB.
800 MHz
0 dB.
300 MHz
-30 dB.
900 MHz
-20 dB.
400 MHz
-13 dB.
950 MHz
-30 dB.
500 MHz
0 dB.
1000 MHz
-54 dB.
BANDPASS PERFORMANCE FIGURES FOR THE 9260
TYPE 9260
BAND
VHF/UHF
FREQUENCY
50-800 MHz (USA) 50-862 MHz (UK)
NOISE FIGURE
0.4 dB.
GAIN
23 dB.
FLATNESS
+/- 1 dB.
MAX. OUTPUT
127 dB microvolts.
MATCHING
Return loss 14 dB.       V.S.W.R. 1.5:1
IMPEDANCE
75 ohms.
CONNECTORS
F sockets.
POWER
+8V. DC @ 73 ma approx.
DIMENSIONS (ins)
L 1.5 x W 2 x H 1.25 ins approx.
DIMENSIONS (mm)
L 48 x W 52 x H 30 mm approx.
CASE
Diecast aluminium.
FINISH
Natural.
TYPE 9254
A wideband version which covers both VHF and UHF.
The unit has transient protection incorporated in both RF and DC paths.
LINK TO PERFORMANCE COMPARISON
WITH OTHER PREAMPLIFIERS
(SUPPLIED BY A CUSTOMER, G.L. DYBWAD, USA)
LINK TO 9260 PERFORMANCE FIGURES
(SUPPLIED BY G.L. DYBWAD, USA)
The types 9260, 9261 and 9267 all combine very low noise with bandpass
filtering to deal with interfering signals. All units have transient protection
incorporated in both RF and DC paths.
           Operating guidelines

In order to obtain the very low noise figures offered we use PHEMT transistors. These are more
sensitive than Mosfets to pulse transients caused by storms. To help combat this we added low
frequency input filtering to the preamps which has proven to be very effective. Since we started
using it less than 2.5% of our customers have had to return units for repair.

An important consideration is that the antenna should be properly grounded to a copper spike. This
gives the transients a direct route to earth and reduces the likelihood of damage by at least 50%.

It's sensible to use a surge arrestor on the mains input, as you would to protect any equipment in
the home.
The 9261 is now available with filtering
to limit the top frequency to 700MHz in
line with recent changes to digital
broadcasting in the United States.

All other specifications remain the same
as the original 9260.

Type 9270
This very low noise, high signal handling capability amplifier is designed to
increase the output of decoders to eliminate drop-outs and pixelization.
It may also be used to compensate for long cable losses and for driving multi
TV outlets. It is designed for indoor use only and is fitted with a feed-through
for local DC supply.
FREQUENCY SELECTION CHART
Choose the best LNA for your wanted reception.
The type 9262 covers VHF and UHF channels with a frequency cut-off at
700 MHz. All other specifications remain the same as the type 9254.
NOW AVAILABLE
TYPE 9263        CH 7 TO CH 51 (USA)
0.4 dB NF                   23 dB GAIN
All noise measurements are made at the output socket of the preamplifier using a fully calibrated
Hewlett Packard noise figure meter.
*** NEW INTRODUCTION - FM/DAB LNA'S ***
FOR IMPROVED RADIO RECEPTION
Type 1301 88-230 MHz
Please note that if we are out of stock of the 9255 we reserve the
right to supply a suitable alternative.