Just found out there is RF issues with Dual Head install using over 40ft of cable between Interface Box and either Remote Head or Radio unit.Kinda sucks if you have a long fire truck/ladder truck to install the kit into.
Anyone seen a SRN or Service Note from Quickmount about this issue yet?
Wayne
Dual Head Kit cable issues ( Quickmount)
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thebigphish
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- What radios do you own?: AM/FM
We have not had ANY QM issues yet.But it has been happening to other installers or shops.A QM distro notified us of it via emailings.QM makes the dual head kits and Motorola brands and sells them now in thier catalogues.This applies only to cable over 40ft long between either Interface boxes and remote heads or box to radio.KE4NYVJR wrote:No, the Quickmount boxes use RJ45 jacks with either 8 conductor flat cable or CAT5 twisted pairs. Either way, no sheilding. We have had MANY problems with these units with CDMs. Usually resulted in toasted QM boxes.
Our recent solution was having to find a spot for the Interface Box to be located somewheres in the middle of the vehicle secured in a pelican case with holes drilled for the cable so go in and out of.
Wayne
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thebigphish
- Posts: 1477
- Joined: Sat Nov 29, 2003 10:10 pm
- What radios do you own?: AM/FM
Yeah,I hope they officially release something.I have heard of 2 more cases where on lowband DM Dual Control Head installations where there was signal loss.QM has me on hold as far any official tech responses.But to be safe we are only running max 40feet cable between either radio/interface box or remote heads.Non function is the symptom,not really fried Interface Boxes ( they are not powered).thebigphish wrote:over 40 feet? Sounds as if signal loss, or timings are getting messed up due to span distance...althought i am not sure why that would toast a QM box...should just lead to non-functionality... hmmm
maybe QM can fess up w/ maximum cable run length or something?
Wayne
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thebigphish
- Posts: 1477
- Joined: Sat Nov 29, 2003 10:10 pm
- What radios do you own?: AM/FM
CDM
QM tech states that their unit will only work up to 40 ft.,that is why they only sell cables no longer than this. If you need a longer run ,try to mount the QM box in between the 2 heads, not always easy to do. Their were issues early on with the LB configuration, thought they had these resolved.
I have found that if you program the CDM for both on/off and ignition sense, the QM unit will shut itself off intermitantly, if you are using ignition sense, program CDM for ignition sense only.
I have found that if you program the CDM for both on/off and ignition sense, the QM unit will shut itself off intermitantly, if you are using ignition sense, program CDM for ignition sense only.
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SonicSounds
- Posts: 32
- Joined: Fri Dec 24, 2004 7:36 pm
quickmount troubles
Got a good one if anybody on here has any suggestions....
Installed dual CDM1250s in a Pierce Dash with quickmount boxes. When the headlights (high beams) are turned out, when the Q2B is pressed, when a hard bump is hit, when the moon lines up just right, etc. the control heads fade to black and then come back up. Sometimes their brightness gets screwed up and you can push the 'light' key to put them back where they belong and sometimes you can't put them back. Sometimes just changing the channel puts everything straight again. Sometimes the backlighting comes back on and no text appears on the display. Its VERY strange. Have probably 8 other QM boxes in use in this station alone, plus other customers with them - no problems at all, let alone something like this.
It is NOT a loose ground or power wire. Have thoroughly checked that. There is a VERY little bit of noise on the DC lines (checked with a 'scope) when the above actions are performed, but you wouldn't think enough to cause a problem.
Suggestions?
Jon
Installed dual CDM1250s in a Pierce Dash with quickmount boxes. When the headlights (high beams) are turned out, when the Q2B is pressed, when a hard bump is hit, when the moon lines up just right, etc. the control heads fade to black and then come back up. Sometimes their brightness gets screwed up and you can push the 'light' key to put them back where they belong and sometimes you can't put them back. Sometimes just changing the channel puts everything straight again. Sometimes the backlighting comes back on and no text appears on the display. Its VERY strange. Have probably 8 other QM boxes in use in this station alone, plus other customers with them - no problems at all, let alone something like this.
It is NOT a loose ground or power wire. Have thoroughly checked that. There is a VERY little bit of noise on the DC lines (checked with a 'scope) when the above actions are performed, but you wouldn't think enough to cause a problem.
Suggestions?
Jon
QM
I had something similar to this in an ambulance. I had the radios and QM boxes wired to the main battery master switch, when the knob was turned on the system came up. I had the CDM programmed for on/off and follow ign. I reprogrammed the CDM to follow ignition only and this solved the problem.
QM said that A+ should be routed to their box at all times, I tried this and the radios would not work when they were turned on via the battery switch. This was on 2 sepeate vehicles. QM said that it was due to a bad ground. I rewired and still could not get the radio to come on. I then went back to the original system where everyting was tied into the main battery master switch and all worked. No idea why the setup by QM did not work.
QM said that A+ should be routed to their box at all times, I tried this and the radios would not work when they were turned on via the battery switch. This was on 2 sepeate vehicles. QM said that it was due to a bad ground. I rewired and still could not get the radio to come on. I then went back to the original system where everyting was tied into the main battery master switch and all worked. No idea why the setup by QM did not work.
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SonicSounds
- Posts: 32
- Joined: Fri Dec 24, 2004 7:36 pm
I just got off the phone with QuickMount (again). The only productive suggestion they had was to run the whole radio setup off a separate power supply (like an Astron) and see if the problem went away. They also suggested a bad ground. The two QM boxes have their OWN awg 10 grounds to a substantial structural member (same place the mobiles and repeaters go to). I mentioned that it was a Pierce Dash because I have never had a wiring problem on any other chassis. I have two installations right now that are 'acting strange' - both in Dash's..... this one and a Kenwood 90 series that has more noise than audio when transmitting...
Jon
Jon
QM issues
Just on a side note - we have installed about 60 Kits over the past 2 years and quite a few of them had problems at one time or another. Mostly it was power problems or channels locking up. All of them were with the CDMs 1550s - what we discovered was that if we changed the QM metal back and swapped it to the Motorola remote mount kit back (RLN4802). All of our problems went away. Recently the Motorola Kit made by QM had some issues also. We ordered a kit and MOT told us they were having issues and were not releasing them. Im not sure if this problem has been resolved since we switched to another radio to solve the problem.
FTM-PTB-EGH-DTRT-RFB-KTF
QM
I have always replaced the QM metal with a Motorola plastci. The first QM metal back were not fitting tight and causing problems.
I have found out with the last few CDM 1250's there is a problem. I program the CDM's to follow ignition only, this seems to work so far.
I have found out with the last few CDM 1250's there is a problem. I program the CDM's to follow ignition only, this seems to work so far.