VHF/UHF Diplexer with VHF > 170 MHz

[hobbes]

I've got a VHF Astro Spectra and a UHF MCS2000 that I'd like to put in the truck. I'm height-limited (garage + truck cap) so I'm pretty much limited to what I can mount off the hood. I've already got a scanner antenna mounted on one side of the vehicle using a L-bracket in the hood groove that works well, figured I'd do the same on the other side with a dual-band antenna.

The problem is that one of the frequencies I need to work with is pretty high in the VHF range -- 173.xxx MHz. All of the diplexers I've seen seem to have 170 MHz as the high point of their VHF bandpass.

Any thoughts? Perhaps a commercial-band diplexer that you've seen with a higher split that I haven't found? Suggestions to avoid the whole dual-band thing in the first place?

As always, thanks for any help.

[akardam]

I'd put a VHF 1/4 wave (tuned to your needs) on an L bracket on the other side of the hood from the scanner antenna, and a UHF 1/4 wave (similarily tuned) on the roof. The UHF antenna will be all of 6-7" tall, and will provide excellent broad-band coverage.

[motorola_otaku]

..and a UHF 1/4 wave (similarily tuned) on the roof. The UHF antenna will be all of 6-7" tall, and will provide excellent broad-band coverage.

And if even that is too tall, PCTEL Maxrad makes a low-profile UHF antenna that covers 430-480 on par with or better than a 1/4-wave whip, and is all of 3 3/8'' tall.