EME226 Relay Kit
- EME226 PC board Description:
Updated! June 2022 - Kit Constructors Alert:
- EME226 KIT Notes:
NEW! July 2021 - EME226 KIT Tests:
NEW! July 2021 - Product Changes and Updates:
- Buy A EME226 Series Kit:
the contact rating of the relay, it should easily handle up to 50
Watts on the 450MHz band. The relay is ideal for antenna switching,
but the isolation between the contacts should be taken into account
when it is used to switch low noise receive pre-amplifiers. Relay
isolation can be improved for a particular frequency band, by
fitting an SMD inductor across the NO contacts on the bottom of the
board.
We have tested this product with 50 Watts on the 70cm band, and 20 Watts on the 23cm bands, and found no evidence of heating due to losses.
The Kit is quite straightforward to construct so no notes are supplied. Care should be taken to make sure that the relay is accurately aligned on the board before soldering it into place. SMA connectors are recommended for the best performance, and need to be soldered on both sides of the board for grounding. Alternatively RG316 coax cable can be used, but good microwave terminations to the board are required. BUY THIS PRODUCT
The picture shows the Basic Kit with optional SMA connectors. The 1N4148 diode is to protect the circuit that switches the Relay.
This picture shows the bottom of the PC board and how the SMA connectors are soldered to the board for good RF grounding. Alternatively miniature coaxial cable can be soldered directly to the board.
S21 relay through loss from the common to the normally connected contacts.
S21 relay isolation from the common to normally connected contacts.
S11 return loss through the relay from the common to normally connected contact terminated into 50ohms.
Picture shows relay isolation when a 1008 2.7uH inductor is used across the normally open contacts. Ideally a 2.4uH is required to shift the resonance up to 145MHz.
Picture shows relay isolation when a 1008 470nH inductor is used across the normally open contacts for resonance on 435MHz.
Picture shows relay isolation when a 1008 56nH inductor is used across the normally open contacts for resonance on 1290MHz. Ideally around 50nH is required to shift the resonance higher.
