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<TITLE>Some answers to call for comments for the design of ALEX</TITLE>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">Comments solicited:</FONT></SPAN>
<BR><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">1. Too many external (BNC) connections? Or not enough?</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">----> I think the amount of BNC's is OK. Individual choices can be made by populating less or all BNC's</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">2. Would you be willing to assemble this yourself, as opposed to purchasing a manufactured module? </FONT></SPAN>
<BR><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial"> It is a mix of through-hole and some surface mount components, and will also require some mechanical assembly. </FONT></SPAN>
<BR><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial"> It is not the kind of assembly that most contract manufacturers are used to dealing with. </FONT></SPAN>
<BR><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial"> I could limit the surface mount components to larger pitch ICs and larger passives.</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">---> I think it will be most cost effective if the boards can be assembled by DIY. (Saves us in the EU probably also up to 20 % VAT as well.......)</FONT></SPAN></P>
<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial"> Larger pitch IC's / more thru hole components is better for people with less DIY experience.</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">3. There are about 20 ea. T-50 toroids and 5 wire coils that will need to be wound. </FONT></SPAN>
<BR><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial"> Would you prefer a kit of pre-wound toroids?</FONT></SPAN>
<BR><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial"> Or would you rather wind them yourself?</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">---> Same as for 2: A kit of pre-wound toroids could be easier for less DIY experienced people and could have the advantage that the coils could have a tested inductance.</FONT></SPAN></P>
<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial"> Also another separate kit for all the other components please if possible !</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">Additional/questions remarks:</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">- Did I miss something and was the digitally continuously tuned preselector/filter idea abandoned and are we back to a number of fixed filters?</FONT></SPAN></P>
<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">- Where is the receiver protection? I think it should be closest to the antenna and as far away as possible from the sensitive electronics.</FONT></SPAN></P>
<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">- Why not use relays for ALL the switches instead of using Hittite switches for the receiver? Simpler BOM, consistency?</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">- What about daisy chaining of filter-boards (e.g. say I want a 16 X RX bandpass filter configuration)</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">- Since it seems we are back to individual filters and seeing the resemblance between the RX and TX block diagrams, would there be a simplification possible by designing just a single board for use in both an RX- and a TX configuration?</FONT></SPAN></P>
<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial"> Filters could be separate modules (as suggested already in the previous discussions) layed out for individual preferences. (Frequency, Filter architecture type, low- high- or band-pass, LNA)</FONT></SPAN></P>
<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">It would contain only the power supply, the relays, the switching logic and mounting space and connection points for the individual filtermodules.</FONT></SPAN></P>
<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">This would require however another separate, (remote- ?) "RX/TX switch over, SWR-bridge, antenna-select, receiver protection" board/unit of some sort.</FONT></SPAN></P>
<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">(Quite a different setup, I am aware of that, but it would be my personal preferred solution)</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">73 's,</FONT></SPAN>
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<P><SPAN LANG="nl"><FONT SIZE=2 FACE="Arial">Henry.</FONT></SPAN>
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