Ham Radio Roofing Filters

Implementing the extra sharp crystal roofing filters provides superior close in dynamic range and affords the best receiver performance possible.

Ham radio roofing filters. Yaesu ft 1000mp mkv field roofing filters. But a roofing filter can be equally at home at a low first if if that is how the radio is designed. Using a more narrow roofing filter can eliminate this unwanted signal and eliminate the agc pumping. 300 hz cw narrow crystal filter the down conversion 9 mhz 1st if frequency receiver construction can realize narrow 300 hz optional 600 hz and 3 khz bandwidth roofing filters.

Inrad has supplied aftermarket and oem crystal filters for amateur radio transceivers and shortwave radio receivers with more than 250 different models available for equipment dating from the 1950 s to the present day since our beginning offering yaesu filters as fox tango international way back in the 1970 s. It is usually found after the first receiver mixer. Upon doing this procedure the audio hiss is greatly reduced enabling much better long time ssb listening and also much better readability. Inrad roofing filters can substantially reduce the third order intermod from multiple strong signals in the 2 20khz range on either side of the tuned frequency.

The goal of a roofing filter is to limit the passband of the first intermediate frequency if stage. 200 hz 400 hz 500 hz 1 8 mhz 2 1 mhz 6 mhz and 13 mhz. In short inrad roofing filter amplifies the input signal. Inrad presently also serves as the oem roofing filter supplier for the popular elecraft k3 k3s series of hf transceivers.

Inrad procedure calls for installing the filter and then reducing the ifgain by 2. Mcf or discrete crystal construction width. For the ft 1000mp the mod is plug in with no soldering required and can be easily removed. Think of the roofing filter as a roof on a house the wide filter allows the dsp and hardware agc to respond to all the rain falling on the roof.

Sized to pass the widest mode of operation improve dr3 begins with. Protects following circuits from nonlinear operation due to strong out of band signals what. To reduce the amount of rain falling on the roof a more narrow roofing filter is required. First filter as close to the antenna as possible 1 st if typical why.

It still provides the same protective function. In my case that moves the if gain from 12 to 10. It comes with a 2 7 khz roofing filter which is very good for all bands and modes. A roofing filter is a type of filter used in a hf radio receiver.

Sales supplies and service. A roofing filter protects later stages including amplifiers mixers narrower filters and dsp subsystems just as the roof on your house keeps rain out ofall of the rooms.