Help on BAND splitting (Diplexer)

[aq_mishu]

amateuradiomalaysia.blogspot.com

I have a base TCVR for Dual band. Now it has a single antenna connector for both uhf and vhf (Icom IC-7000). I have to receive the entire band of 60Mhz to 999Mhz. Also while Tx, I want to use 144-148 and 430-450. So for RX and TX, I need actually 2 antenna. one for TX in vhf and one for TX in uhf. now I need to use single feedline till the 2 ANT. so at the ANT part, i can use a band splitter. So my plan is one will allow from 60 to 400 and another will allow from 400 to 999. So guys give me ideas...

 

[vfone]

Is not very clear for me what are you using to receive from 60MHz to 999MHz when IC-7000 can receive only from 0.3MHz to 200MHz and from 400MHz to 470MHz.
Whatever you use for receiving, IC-7000 needs a diplexer for using the transmitters for both VHF and UHF bands.
Cannot use a power splitter for splitting VHF and UHF bands due to the mismatch that will appear at the ports of the splitter.

 

[aq_mishu]

yup... i mean i dont want to loose any rcv.. it has 2 ant conn. one for hf+50mhz band.. other for uhf+vhf. thus i have to use one feed line for uhf+vhf. another feed line for hf. and in that case, i have to split the band for Tx. and i need the entire band (that it can) for rx... thus need to split it in some way so that it can do rx and tx both in 2 different ant with a single feedline... ideas???

 

[vfone]

https://amateuradiomalaysia.blogspot.com/2005/09/diplexer-for-hf6m2m-70cm.html

 

[aq_mishu]

well, i have checked it... matter is, for ic 7000, there are again 2 ant conn.. one for upto 60mhz... and another is for more than 60mhz till the uhf. now i'll get a feed line (dedicated) for hf+50 (upto 60mhz). but shared feed line for vhf and uhf. so iwant to split it with the range of 60> x < some value more than 175. and another range some value more than 175 > x <999 mhz. for example, 61>x<200 and 202>x<999. this is because i may use another set (regular vhf and uhf) and also i want to rcv the entire spectrum (using ic 1500) with the same feed line. help me in this regard plz...

Note: the previous one is splitting hf and vhf+uhf. but i can tune it according to my need only after the math....

 

[vfone]

All right. Already appear another device in your system (IC-R1500).

You have to switch the Ant2 of IC-7000 and the antenna of IC-R1500 using a coaxial switch (to prevent damaging the input of the IC-R1500 with the power of IC-7000).

Cannot use a power splitter instead, due to limited isolation between ports, but especially because of the 3dB insertion loss which will halve your output power.

The common port of the switch goes into a wideband diplexer which splits the VHF and UHF transmit bands, and covering in the same time receiving frequencies up to 999MHz (actually IC-R1500 can receive up to 3300MHz).
The high-pass branch of the diplexer should be wide band.