Several of my UHF MTS2000's and other Jedi's are a bit deaf compared to my Waris and XTS stuff.
I have often thought that they actually sound a bit off frequency but the TX ref Osc is spot on (say +/- 200Hz)
I'm thinking that the problem might actually be the RX 2nd LO crystal being off frequency.
I checked the service manual and I think the 2nd LO crystal is on 73.35MHz.
I went though several Jedi's with a test receiver and looked for a zero beat on 73.35MHz.....I got the best signal half way up the Jedi on the back of the radio..the 2nd LO is very weak but easy to detect.
The Jedi which sounded most off freq zero beated on 73.351200 MHz. (Others were on around 73.350400 and 73.350200 MHz)
If I am correct, this suggests that the 2nd LO on the above radio is 1.2KHz off frequency..which I guess results in the actual RX freq being 1.2KHz off freq..although the TX will be spot on.
I think a 1.2KHz error WILL be noticeable on a weak signal, especially if the received signal is a bit off freq in the "other direction".
Am I correct in my above assumptions?
Is there any way to adjust the 2nd LO frequency or is this set up in the factory?
Is an off freq 2nd LO crystal a common issue with Jedi radios?
Thanks
- Board index General General Motorola Solutions & Legacy Radio Discussion
- Search
-
- It is currently Sat Jun 15, 2024 8:26 pm
- All times are UTC-08:00
MTS2000 UHF - 2nd LO crystal off frequency??
The General forum is where users can discuss any topic regarding Motorola communications equipment - hardware, software, etc. There are also several focused forums on this board, so please take the time to ensure that your questions doesn't fall into one of those categories before posting here!
Moderator: Queue Moderator
Return to “General Motorola Solutions & Legacy Radio Discussion”
Jump to
- Administrative
- ↳ Announcements and Forum News
- ↳ Forum Rules
- General
- ↳ General Motorola Solutions & Legacy Radio Discussion
- ↳ Radio Programming
- ↳ Software & Firmware Releases & Issues
- ↳ Codeplug Information
- ↳ NFPA 1802 Discussion
- Current Motorola Solutions Public Safety / Astro Product Line
- ↳ APX NEXT
- ↳ APX Series Subscribers
- ↳ ASTRO Series (Astro Saber, Spectra, XTS3000/3500) Subscribers
- ↳ ASTRO25 Series (XTS/XTL 1500/2500/5000) Subscribers
- ↳ ASTRO Experimental - How to do things a little out of the box
- ↳ ASTRO Products Feature Requests & Future Speculation
- ↳ Legacy Batboard Motorola ASTRO (VSELP/IMBE/AMBE) Equipment Forum
- Current Motorola Solutions Professional / Business Product Lines
- ↳ MotoTRBO ION Devices
- ↳ Motorola CP/CM Series Subscribers
- ↳ MotoTRBO Portables and Mobiles (4xxx/6xxx) 1.0 Series Subscribers
- ↳ MotoTRBO Portables and Mobiles (3xxx/5xxx/7xxx/SL) 2.0 Series Subscribers
- ↳ MotoTRBO Repeaters, Trunking, and Site Infrastructure
- ↳ MotoTRBO 3rd Party Application Discussion & Support
- ↳ MotoTRBO/Business Products Feature Requests & Future Speculation
- ↳ Experimental - How to do things a little out of the box
- Motorola System Infrastructure (Consoles, Base Stations, Repeaters, Trunking, etc.)
- ↳ Smartnet/Smartzone/Project 25 (Phase I/II) Systems
- ↳ Base Stations, Repeaters, General Infrastructure
- ↳ Consoles
- ↳ Experimental - Mods, and how to do things a little out of the box
- ↳ Infrastructure Product Feature Requests & Future Speculation
- Focused Discussion
- ↳ Motorola Digital and Voice Paging
- ↳ Converting Motorola Equipment to 900MHz Amateur
- ↳ Test Equipment & RF Equipment Alignment
- ↳ Vehicle Radio Installs
- ↳ Experimental and Next Generation LMR
- ↳ Motorola Digital Radio Compatability
- Off-Topic Discussion
- ↳ Vehicle Warning Equipment Discussion
- ↳ Computer/Technical Assistance
- ↳ Knowledge Base