As of February 2017 the Sharp and Samsung NIMs are no longer available and the MiniTiouner project will use a NIM from Serit (FTS-4335) which covers from 143.75MHz right through to 2450 MHz without the need for any upconverters.
The first prototype was shown at CAT16 by Jean-Pierre F6DZP - you can watch a video of his presentation on the BATC Youtube channel.
Why should I buy a Serit tuner?
- You should buy one if you already have MiniTiouner hardware and you want to be able to receive 146 MHz and 70cms without building an upconverter.
- You should buy one if you already have MiniTiouner hardware and want to experiment with the higher DVB-S2 modes such as 32APSK which the Sharp NIM cannot demodulate.
- You should buy one if you have not yet built a MiniTiouner receiver as the previous Sharp tuner went obsolete.
- If neither of those apply, you don't need one! It does not perform any better than a Sharp - in fact it needs more gain in front of it.
Due to a different pinouts from the Sharp NIM, the Serit FTS4335 NIM will also need a simple adapter board to enable it to be plugged in to the MiniTiouner.
Brian G4EWJ has designed a PCB and the blank board plus a full set of (leaded) components and the Serit FTS-4335V NIM is available in the BATC shop.
The adapter card build instructions, Parts List, Schematic and silkscreen print are in this zip file:
Please use the BATC forum for any feedback on this project http://www.batc.org.uk/forum/viewtopic.php?f=15&t=4853
Note: As of April 2017 a new main PCB is being designed to directly take the Serit tuner - any new constructors should wait for the new board which will not need the adapter PCB. You only require the adaptor PCB if you are upgrading existing MiniTiouner hardware to include the Serit tuner.
Filters and pre-amps
The wide band coverage makes building a receiver for 146 or 437 much easier, although you will need a pre-amp followed by lots of filtering for each band, just like the Sharp did, and probably followed by a Satellite line amp from ebay as the Serit FTS-4335 has less gain than the Sharp.
To use the FTS4335 NIM with the MiniTiouner, you will need to run Ver 0.6d or later versions of the excellent MiniTioune software. This is available for download from the Viva DATV forum here and will work with Sharp, Eardatek or Serit NIMs. You need to register on the Viva DATV forum before being able to download.
The Serit FTS4335 NIM is capable of receiving more than one signal simultaneously; however the BATC hardware and software can only receive one signal at a time. There is provision for a socket on the converter PCB to connect to the second receive output of the FTS4335V for experimentation. F6DZP's dual receive software is still under development and may be available for testing. See his web site at: http://www.vivadatv.org
Even though only one transmission can be received at any time with this converter PCB, it is possible to select which of the two antenna sockets is used, allowing one of two antennas / converters to be connected.
If you want to attempt to hardwire the Serit tuner, the pin differences between Sharp and Serit are as follows:
This picture from the http://www.vivadatv.org/ site shows the interconnection: