Customized RF Components and Microwave


Amateur radio is a popular technical hobby. Radio amateurs use a wide variety of radio communications equipment to communicate with each other and provide emergency communications for their communities. Radio amateurs have their own communications satellites. They can talk with astronauts aboard the International Space Station. They are often involved with cutting-edge experimental wireless technology. It is a very popular interest with over six million people involved worldwide.

Amateur radio satellites have interference problems by other amateur radio stations. And there are variety of apparatus have caused severe interference to amateur satellites. It could result in mission failure. Therefore, they will need high attenuation filter to protect their networks from interference.

Attenuation curve or transmission curve means a curve relating the value of a radiation quantity and the thickness of material traversed by the radiation. Attenuation limits the range of radio signals. Attenuation typically is measured in decibels (dB) or voltage. Attenuation can happen with any type of cable or wireless connection, including copper cables, fiber cables, satellite, radio signals, wireless networks. Attenuation is an important consideration in wireless telecommunication. Attenuation can occur due to a variety of factors. It may cause signals to become distorted or indiscernible. E.g., Wi-Fi signal and strength getting noticeably weaker the further that your device is from the router.
The problem of amateur radio satellites interference is likely from radio, TV broadcasts, aircraft communications, transceiver, repeater, radar, two way radio, etc.

proimages/application/4pole-ham/4P-Filter.jpg proimages/application/4pole-ham/TM-Filter.jpg
Temwell has 26 years of experience in designing, producing and marketing helical band pass filters. The helical band pass filters are used λ/4 wavelength technology to design. Our helical band pass filters have high attenuation characteristics. The steep attenuation could provide highly effective radio noise suppression.

Temwell special provides 146 MHz, 232.5 MHz, 435 MHz, 915 MHz, 1270 MHz and 1282.5 MHz standard band pass filters for ham radio users. The helical band pass filters have excellent noise interference suppression and do not affect the quality of communication. All models are available from stock. Welcome to visit our Shopline Store to check and take your prefer filter.

A. Frequency: 146MHz Spec (Freq / BW) Size (LxWxH)   Accepted Type
TF69709B-146M 146MHz / 5MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF69281A-146M 146MHz / 8MHz TF (30.5x7.6x12.5) Pin Type / Module Type

B. Frequency: 223.5MHz Spec (Freq / BW) Size (LxWxH)  Accepted Type
TF6434B-223.5M 223.5MHz / 8MHz TF (30.5x7.6x12.5) Pin Type / Module Type

C. Frequency: 435MHz Spec (Freq / BW) Size (LxWxH)  Accepted Type
TF69410B-435M 435MHz / 31MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF69295B-435M 435MHz / 34MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TFW4630B-435M 435MHz / 26MHz TFW (22.4x5.6x8.6) Pin Type / Module Type
D. Frequency: 915MHz Spec (Freq / BW) Size (LxWxH)  Accepted Type
TF69748B-915M 915MHz / 26MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF69550E-915M 915MHz / 27MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TFW4553B-915M 915MHz / 29MHz TFW (22.4x5.6x8.6) Pin Type / Module Type
TFW4684B-915M 915MHz / 25MHz TFW (22.4x5.6x8.6) Pin Type / Module Type

E. Frequency: 1270MHz Spec (Freq / BW) Size (LxWxH)  AcceptedType
TF69810B-1270M 1270MHz / 60MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TFW4759B-1270M 1270MHz / 65MHz TFW (22.4x5.6x8.6) Pin Type / Module Type

F. Frequency: 1282.5MHz Spec (Freq / BW) Size (LxWxH)  Accepted Type
TF64753D-1282.5M 1282.5MHz / 25MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF69751B-1282.5M 1282.5MHz / 27MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TFW4575B-1282.5M 1282.5MHz / 29MHz TFW (22.4x5.6x8.6) Pin Type / Module Type

On Shopline Store we build over hundreds of standard helical band pass filter. Filters are ready-made and could be delivered within 72 hours. It is readily hand solderable, pin type, power 5 watts, acceptable fine-tune the frequency and no minimum order quantity. For small quantity requirement, Temwell Shopline Store is the best and cost effective selection. Click Temwell Filter Store to see details.

Our band pass filter DIY Test Circuit Kit is also very suitable for ham radio user. The DIY Test Circuit Kit provides one tripe tuning helical band pass filter, one PCB, two SMA connector, three filter screw for tuning and four long screw as kit pillar. You can select the filter you need from Triple Tuning Helical Filter. The price is very favorable. Now contact us for more information. Email: sales@temwell.com.tw