No need to spend $110 or
more for a good, low-noise FET preamp! Our LNY-( ) Preamp is only $39,wired/tested.
Unlike other FET preamps on the market, this one uses
one of the new-generation, very-low-noise, dual-gate MOS FET's
which are designed exclusively for use in the vhf & uhf bands.
They have built-in diode protection and very low feedback
capacitance, resulting in good stability and rugged performance
under a wide range of voltage, signal, and load impedance
conditions. Note that there is a recent trend to use silicon
rather than galium arsenide at vhf and uhf frequencies. New
techniques provide better noise figure than we got with
comparable GaAs FET's only a few years ago.
Some units you may see on the market use triode fet's designed for microwave, and they are not always stable when operating at vhf and uhf frequencies. Most don't have any built in diode protection; so they must be handled very carefully. Some companies even use bipolor transistors, which are cheap but notorious for intermod. The FETs used here are designed exclusively for use at these frequencies; so they don't easily oscillate. And replacement fet's are relatively inexpensive.
Surface mount technology is used to obtain minimum noise figure and best stability. We are able to produce these preamps wired and tested for the same price kits cost for earlier models. Therefore, they are offered only as fully factory assembled and tested units.
The preamp is connected in series between the antenna and the receiver to effectively lower the noise figure of the receiver front end, allowing weaker signals to be received. The LNY series was designed for operation in 50 ohm systems; however, they will operate satisfactorily on 75 ohms as well.
| Miniature Preamp, only 1 x 2-1/2 x 1/2 in. high. | |
| Easily mounts inside many radios. | |
| Low noise figure to hear weak signals. | |
| Rugged, diode-protected, new-generation dual-gate silicon FET's. | |
| Wide dynamic range for overload resistance. (1dB compression @ +5dBm) | |
| Operates on +12 to +15Vdc @ 10mA; no special power supply required. | |
| RCA input/output connectors for easy connection. | |
| Easy to tune | |
| Shipping weight 1 lb |
MODEL |
TUNES RANGE |
FACTORY PEAKED |
TYP.NOISE |
GAIN |
MIN. 3DB |
LNY-146 |
130-160 MHz * |
146 MHz | 0.6 dB |
18 dB |
±4 MHz |
LNY-220 |
195-240 MHz |
224 MHz | 0.7 dB |
18 dB |
±5 MHz |
LNY-450 |
400-470 MHz |
448 MHz | 0.8 dB |
18 dB |
±5 MHz |
|
LNY-WB |
2-1000 MHz |
- |
5.0 dB |
** |
** |
| Also, see LNK series preamps for many more frequency ranges. | |||||
|
Note: Units are easily repeaked at your operating frequency after installation. They are stocked tuned to center frequency indicated above. If you prefer, we can custom tune to your frequency at an additional charge of $10. However, if your operating frequency is within 2-3 MHz of the center frequency specified, special tuning is unnecessary. ** LNY-WB is a wideband preamp intended for scanners, tv, fm broadcast, service monitors, etc., which require wide band amplification. It uses a microwave bipolar transistor, and the gain varies from approx. 15 dB at the low frequency end of the range to about 10 dB at 500 MHz and 7-8 dB at 1000 MHz. Because it has no selectivity, it is not recommended for applications in a high rf environment where selectivity is essential to avoid overload or intermod interference. |
|||||
WHEN IS A PREAMP BENEFICIAL?
It is tempting to hope that a preamp can make any receiver more sensitive, in any situation. But, it is important to understand what happens when you add a preamp before a receiver.
A preamp can help overcome a deficiency in receiver sensitivity only if the noise figure is poor, either due to the design or because a lossy filter or cable adds to the noise figure. For instance, a preamp up at the antenna can overcome the effects of coax cable loss.
However, adding gain in the front end raises all signal levels; so, in effect, every dB of gain added overrides one dB of if selectivity or dynamic range. Therefore, adding a preamp can result in intermod or desense. The only way to know is to try it.
PF-1 PHANTOM POWER KIT $5Often, we are asked if the +12Vdc power for the preamp can be fed up the coax cable from the receiver for installations where the preamp is mounted at the antenna. We have long resisted the temptation to try to save a few cents on some light-weight hookup wire by using this trick, feeling that chances of messing up the rf performance are too great. We now offer a kit for those who want to try this anyway. It consists of the rf chokes and dc-blocking capacitors needed for both ends of the cable, at the receiver and the preamp, along with general instructions. It may be used on any frequency from 130-500 MHz. |
| LNY-( ) Preamp, wired/tested.... $39.00 (specify model from chart above) | |
| A5 RCA plugs. A special rf type plug with cable clamp...$0.75/each | |
| A27 Miniature Coax Cable ...6ft/$3 | |
| PF-1 Phantom Power Kit option (see sidebar above) ...$5.00 | |
| A40 AC adapter ...$9.50 |
I installed the preamplifier you recommended in my Hamtronics 220 repeater
and it is working great! Thanks for the guidance in using the LNY 220 pre-amp.
The cost was low and the performance is remarkable! I was able to use my HT 35
miles from the repeater with only 1/2 watt of power.
... Del R.
Wow, I purchased the LNY-166 (tuned to 161) and am totally thrilled with its
performance! I set up a 'T' connector with the antenna so that amplified signal
would go into one radio and non-amplified signals go into the other. It was
crystal clear how much improvement the amp makes! ... Josh O.
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