LNK Receiver Preamp

You can hear the weak ones, too, and without spending a fortune!

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 gallium arsenide at vhf and uhf frequencies. New techniques provide better noise figure and stability than we got with comparable GaAs FET's only a few years ago.

Surface mount technology is used to obtain minimum noise figure and best stability.

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 LNK series was designed for operation in 50 ohm systems; however, they will operate satisfactorily on 75 ohms as well.

The unit can be mounted outdoors if you seal around the case with silicone. You can also enclose the entire preamp in pvc pipe as shown on this website.

FEATURES:

Small Size: only 1-1/2 x 3-1/2 x 1-1/8 in. high (plus connectors)
Easily mounts inside shack or up on tower (receive only applications).
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)
Easy to tune
Operates on +12 to +15Vdc @ 10mA; no special power supply required.
BNC input/output connectors for easy connection. (sorry, cannot change to N connectors)
Power on hookup wire (24" supplied), using coax shield for ground.
Shipping weight 1 lb

MODEL	TUNES RANGE	FACTORY PEAKED	TYP. NOISE FIGURE	GAIN	MIN. 3DB BANDWIDTH
LNK-50	35-63 MHz	52 MHz	0.6 dB	24 dB	±3 MHz
LNK-137	130-160 MHz *	137.5 MHz	0.6 dB	18 dB	±4 MHz
LNK-146	130-160 MHz *	146 MHz	0.6 dB	18 dB	±4 MHz
LNK-166	150-180 MHz	166 MHz	0.6 dB	16 dB	±5 MHz
LNK-220	195-240 MHz	224 MHz	0.7 dB	18 dB	±5 MHz
LNK-450	400-470 MHz	448 MHz	0.8 dB	18 dB	±5 MHz
Note: Units are easily re-peaked 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 $20. However, if your operating frequency is within 2-3 MHz of the center frequency specified, special tuning is unnecessary. * LNK-137 and LNK-146 are same unit, just tuned differently.

See what customers have to say...

Wow, I purchased the 166 MHz preamp 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.

PRICES:

LNK-( ) Preamp, wired/tested ...$99.00 (specify model from chart at left)

LNY-( ) Preamp, wired/tested ...$79.00 [this is same preamp but without the case, RCA jacks on board for coax connections.

Tuning charge if you want it tuned to custom frequency ...$20

A40 115VAC/12Vdc Power Adapter to power this unit ...$10.00

PF-1 Phantom Power Kit option ...$5.00
Often, 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.

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.