Elecraft k3 which filters

Price Increases Coming November Orders placed before November 15, will be honored at the lower prices. The K3S transceiver has been optimized for the ham bands. This has been borne out by its popularity with DXpeditions and Contesters. For many people who are upgrading their stations, the K-Line also provides many options they can choose from.

At Elecraft, we get many calls about how to make these decisions. This Application Note offers you a method to determine how you can purchase just what you need for your operating preferences.

Now that you have an idea of where your operating priorities are, here are some K3S configurations that you can order immediately. See next table for filter combinations. Now that you have determined your operating preferences and the configuration of your rig, let's turn our attention to the selection of filters. But a roofing filter can be equally at home at a low first IF, if that is how the radio is designed. It still provides the same protective function.

When we released the K2 in , we never described our 1st IF crystal filters as roofing filters. We had only one IF, so the receiver model was simpler; there were no narrow filters at later stages that required protection. But now, we find that the term is in widespread use. Average hams now think of roofing filter bandwidths as the standard of comparison between receivers. This is why manufacturers have jumped through hoops to try to provide the narrowest possible roofing filters. Many operators have an understanding justified that a roofing filter that is wider than the communications bandwidth will not best protect the receiver's later stages.

In recent years, the roofing filter has become the centerpiece of receiver redesign: Suppose that manufacturer "A" initially designed their receiver to use a or kHz roofing filter. Yes, this allows the receiver to handle NBFM and other wide modulation modes; it may also be selected to constrain the signal bandwidth ahead of a noise blanker or spectrum scope. But it comes at a price. If you're using CW mode, you'll have much narrower filters selected at the radio's 2nd and 3rd IFs.

Yet the 1st IF roofing filter allows a broad swath of signals into the earlier stages. You don't need this energy in your passband. It can cause trouble.

Manufacturer "A," realizing they have a problem with dynamic range at close spacing, then announces that they've had a breakthrough: they can now offer a 6-kHz, or more recently 3-kHz roofing filter. So why don't they offer much narrower roofing filters that can be switched in for CW and data modes, or at times when adjacent-channel SSB QRM is very high? It's because they can't make filters any narrower at such a high IF. Enter the "down-conversion" rig K2, K3S, Orion, etc. By converting to a low first IF, the designer can easily create narrow filters that are compatible with the required communications bandwidth.

This is why we are offering filters with bandwidths as low as Hz. And yes, these are still "roofing" filters, because they limit exposure bandwidth , thus protecting later stages in the K3S case, the IF amp, 2nd mixer, and DSP. Crystal filter installation is covered in detail in Appendix A pg. Once filters have been installed or moved , follow the steps below.

The K3 Utility software application can also. Filter Bandwidth. Use the filter information table you filled out in Appendix A. Filter Frequency Offset. The default value,. Most 5- pole filters will have an offset, e.

This has no effect on performance; firmware compensates for the offset.