Offset Attenuator (4 MHz) can be used on 23cm(1300Mhz) sold without 9V Battery
The battery is retained by two M3 cap screws for easy access and to keep the box small and light.
A fox hunt attenuator is one of the tools that is indispensable when tracking down foxes or rouge transmitters.
Double sided Through hole plated PCB, uses approx 4ma from a 8.4V Lithium pack (designed for nominal 9V operation)
Comes with 4.00Mhz crystal, we have selected other frequencies available.
The why and how of a mixing/active attenuator
Normal switched attenuators will give up to about 30dB attenuation, this is usually not enough, this is where the mixing/active attenuator comes in. These attenuators is based on a diode mixer, there is a huge selection of diodes available, the diode that is used in this unit is usable for frequencies up to 2Ghz.
These are default with 4Mhz oscillators that would produce an offset image above and below the wanted frequency. By storing the target frequency and the target frequency-4Mhz (or target frequency+4Mhz) in two adjacent memory channels, would make the switch between attenuated and non attenuated signals nearly instantaneous.
Be careful of transmitting into an attenuator, it is possible to damage the mixing diode, it also causes harmonics in you transmission signal,
See http://www.lrlabs.com/hams/kits/attenuator/index.html for circuit diagram and operation.
We can also make the unit in other but 4Mhz frequencies, contact us for with your requirement.