Firekite
Member
- Joined
- Apr 2, 2019
- Messages
- 471
I’m planning my mobile setup for my truck. I’ll most likely end up with one mobile VHF/UHF transceiver, and I have a Uniden BCD436HP scanner. I’d like to look at using a single dual-band antenna to service both devices.
I know I can install two separate NMO mounts with two separate antennas, and as long as the RF coupling between the antennas is reasonably low at transmit frequencies at full transmit power, the scanner would probably be ok and neither significantly desense over time nor for that matter burn out the front end.
Before I decided to make the leap to getting my ticket and therefore having to take transmit into account, I’d considered primarily the Larson NMO150/450/758 as a great scanner antenna for my needs. Now I’m also considering the NMO2/70B instead even though it’s twice as long and lacks a spring, just for the extra transmit gain.
What I’d really like to do is simply go with a single antenna (not sure which yet) on an NMO mount centered on my roof with a single LMR200 feed line to a single point where it can then be shared by both the mobile radio and the scanner. But I can’t imagine I can use a simple splitter without murdering the scanner. Am I overthinking this? Do the modern x36/SDS Uniden scanners have reliable RF sense overload protection of some sort built in? If not, I assume I need a transmit-receive switch to protect the scanner. Right?
It seems like most “affordable” transmit-receive switches these days are targeted toward SDR users to protect their receiver in a base shack. I’m not sure why, other than maybe it’s just the most common use case for such a component these days. Is there something magic about SDR I’m not aware of that would make such a switch specific to SDR? Or since a scanner is simply a receiver, would something like the MFJ-1708B be an appropriate choice for this sort of mobile application?
I know I could get a second antenna and NMO mount setup for about the same price, but I’m trying to keep things simple and minimize the number of antennas I have to get out and remove when entering my garage, car washes, etc, and I can’t imagine scanner reception would be any better on a separate antenna. And I don’t really need (or want) my scanner to be receiving and blaring as I transmit anyway.
Am I on the right track? Is there a perfect solution I just haven’t found yet? Insights and experiences would be welcome, as this is my first rodeo making these kinds of plans and decisions.
I know I can install two separate NMO mounts with two separate antennas, and as long as the RF coupling between the antennas is reasonably low at transmit frequencies at full transmit power, the scanner would probably be ok and neither significantly desense over time nor for that matter burn out the front end.
Before I decided to make the leap to getting my ticket and therefore having to take transmit into account, I’d considered primarily the Larson NMO150/450/758 as a great scanner antenna for my needs. Now I’m also considering the NMO2/70B instead even though it’s twice as long and lacks a spring, just for the extra transmit gain.
What I’d really like to do is simply go with a single antenna (not sure which yet) on an NMO mount centered on my roof with a single LMR200 feed line to a single point where it can then be shared by both the mobile radio and the scanner. But I can’t imagine I can use a simple splitter without murdering the scanner. Am I overthinking this? Do the modern x36/SDS Uniden scanners have reliable RF sense overload protection of some sort built in? If not, I assume I need a transmit-receive switch to protect the scanner. Right?
It seems like most “affordable” transmit-receive switches these days are targeted toward SDR users to protect their receiver in a base shack. I’m not sure why, other than maybe it’s just the most common use case for such a component these days. Is there something magic about SDR I’m not aware of that would make such a switch specific to SDR? Or since a scanner is simply a receiver, would something like the MFJ-1708B be an appropriate choice for this sort of mobile application?
I know I could get a second antenna and NMO mount setup for about the same price, but I’m trying to keep things simple and minimize the number of antennas I have to get out and remove when entering my garage, car washes, etc, and I can’t imagine scanner reception would be any better on a separate antenna. And I don’t really need (or want) my scanner to be receiving and blaring as I transmit anyway.
Am I on the right track? Is there a perfect solution I just haven’t found yet? Insights and experiences would be welcome, as this is my first rodeo making these kinds of plans and decisions.