3720/3820 Questions

[natedawg1604]

So I'm seriously considering getting a 3720 and 3820 for my vehicle, I would use them for Ham and (with the VHF unit) scanning railroad channels, forest service and a few other things. I'm also considering the XPR 5550, but it appears the Kenwood's have a higher scan list capacity and also a slightly smaller form factor. Anyhow, I have a few questions about the 3720/3820:

1. What is the scan list capacity? I've never programmed Kenwood radios before, and the documentation I found doesn't specify.

2. Does anyone know the approximate scan speed?

3. Does the DMR site roaming/vote scan feature work similarly as compared to Moto XPR? I can't find much documentation about programming these things, I'm guessing I would need to buy the KPG software and check out the embedded help files.

4. Overall, can anyone comment on how these units compare with the XPR 5550 (other than the absence of NXDN mode of course)?

 

[natedawg1604]

Wow I thought more people would be familiar with these radios. Can someone at least tell me the scan list capacity of the NX 3000 series?

 

[mmckenna]

I think it's 128 scan lists with up to 31 members in each list.

Scan speed isn't something that's published since these are not scanners. They will scan, but they are not as fast as a consumer scanner. If you are going to load this down with a ton of scan lists, you may be disappointed if you are looking for fast scan speeds.

Never used on in DMR mode, so I'm not much help there.

 

[natedawg1604]

I think it's 128 scan lists with up to 31 members in each list.

Scan speed isn't something that's published since these are not scanners. They will scan, but they are not as fast as a consumer scanner. If you are going to load this down with a ton of scan lists, you may be disappointed if you are looking for fast scan speeds.

Never used on in DMR mode, so I'm not much help there.

Yeah I was just thinking about that exact issue, in fact you raise a really good point. I currently have a XPR 6550 and I love the audio quality, sensitivity and selectivity for railroads, forest service, LE/FD agencies on vfh etc; I just don't like the low scan list capacity. I also really like the lack of intermod and related hardware issues you get with scanners.

I've never tried to test the scan speed of my XPR, I guess I should put in some NWS freqs to test it out.

Maybe I should get several XPR 5550s in VHF and just stick with Moto, as I already have the MotoTrbo CPS; I would just have to get the mobile programming cable.

If the scan speed of all the commercial radios is pretty slow for conventional, there is obviously no point in creating a huge scan list. In fact the more I think about it, some of my SDS favorites lists have like 125 freqs and it takes a while to scan through everything.

I'm planning on putting these Mobile radios in my vehicle, my ultimate goal is to make less adjustments to stuff while driving. However there is obviously a limit to how many radios a person can monitor while driving, I guess I will need to consider this as well.

 

[mmckenna]

Some railroad operations use NXDN, so investing in a DMR only radio if you want to listen to railroads may not be the best plan.

I ran Motorola stuff at work for a long time. I switched to Kenwood back in 2011 and never looked back. More bang for your buck, and less B.S.

As for scanning, yeah, commercial radios are not scanners and usually disappoint scanner users. For most public safety use, scanning is a bad thing and has to be very carefully implemented. Huge scan lists are a problem, and most agencies don't need more than a few channels in scan. But Kenwood is way out in front of Motorola when it comes to scan capability.

 

[wd8chl]

Only comment I can add is that roaming, at least DMR, works more the way I expect it to than other DMR radios, in that if you are in roam, and you hit PTT, it will cycle through all of the channels in the roam list until it finds one that it can access. Most others will only try the repeater channel you have selected, and gives up if it doesn't work.

 

[natedawg1604]

Update: so after checking Fleabay for quite a while I found an insanely good deal on a couple of 3720s. It appears there aren't many of these radios on the used market right now.

Hopefully I can get the Software pretty quickly and start getting familiar with it.

 

[mmckenna]

Yeah, they are fairly new, so not surprising.

 

[natedawg1604]

So I need to ask a really stupid question, what type of RF connector does the 3720/3820 use? I checked the service manual and for the antenna connector part it states "ANT M". What the f*&$ does that mean?

 

[mmckenna]

UHF/PL-259

 

[AK9R]

...for the antenna connector part it states "ANT M"...

I believe that in Japan, what we call "PL-259" or "UHF" connector is called an "M" connector.

 

[natedawg1604]

I believe that in Japan, what we call "PL-259" or "UHF" connector is called an "M" connector.

Wow I can't believe they aren't using TNC or at least BNC. But such is life.

 

[mmckenna]

Wow I can't believe they aren't using TNC or at least BNC. But such is life.

On the 700/800/900MHz radios, Kenwood uses N connectors.

But I agree, using N on VHF and UHF would make some sense, but I guess it's making it easy for swapping out old radios. I think Harris uses TNC, and of course Motorola with Mini-UHF and the QMA or whatever they are running on their newer radios.

 

[wd8chl]

In fact, Motorola actually commissioned AMP to make the "mini-UHF' back in the 70's. They wanted a connector similar to the UHF, but constant impedance, and good to over 1 GHz. Why they didn't just use existing connectors, I don't know. Must have been size related...

Meanwhile, I think on using UHF connectors-they are easier to install than N or T/BNC. On those, the strip has to be just right, where on crimp PL-259's, it isn't so critical if you strip the center back a long way. In fact, you kinda want at least 1/4 to 1/2" sticking out of the pin so you can cut it flush. Oh, and they're much cheaper too...

 

[mmckenna]

Meanwhile, I think on using UHF connectors-they are easier to install than N or T/BNC. On those, the strip has to be just right, where on crimp PL-259's, it isn't so critical if you strip the center back a long way. In fact, you kinda want at least 1/4 to 1/2" sticking out of the pin so you can cut it flush. Oh, and they're much cheaper too...

On the commercial side (where these Kenwood radios are marketed), installation isn't a challenge. Most of us have done thousands of them in our lifetime. Price really isn't much of a difference if you are buying high quality connectors.

As for the mini-UHF, Motorola has a history of doing things a bit differently.

 

[natedawg1604]

Update: so I now have 2 3720's sitting on my desk, after scouring various sources I found a fabulous deal (hard to find these days). So far I've only had time to update the firmware and play with the software a little, but I can already see these are amazing little radios, they are so compact that I may not even bother getting remote heads for my vehicle. The software is interesting, it seems to have a very clean UI design and a good help menu, it's real easy to use.

Having never used Kenwood radios/KPG CPS before, I found the firmware update process very straightforward. I am using an aftermarket programming cable from BlueMax49ers, it seems kinda slow but it worked fine. Does anyone know if the OEM Kenwood cable would be faster, and/or if the programming/updates are done through a serial protocol or something else? It's not a big deal, I was just curious.

 

[kd4efm]

kpg-46XM, the radio is native USB mode, the UART switch is for slower PC's, but you can also get BTSPP (bluetooth programming license)
KWD-3002BT for around 30$ if you have Bluetooth enabled laptop/pc.

kpg-46xm 138.00 with shipping.
enjoy!

 

[Cognomen]

The Kenwood KPG-46X cable is faster for the NX-3000 and NX-5000 series mobiles. If you aren't updating/programming batches of radios where the time really adds up, just stick with the Blue Max cable.

 

[natedawg1604]

Okay so I have another pretty basic question about the 3720, it probably applies to a lot of Kenwood Radios. When creating scan lists in KPG-D3N, is the scan speed impacted by using a scan list and creating scan members from numerous systems/zones, as opposed to using a single-zone scan list with the same number of scan list members? Or is the scan speed solely based on the number of scan list members, regardless of how it's setup (i.e. single zone vs. multi-zone vs. scan list)?

 

[mmckenna]

I've never noticed a difference on my NX-3400 or any of the other NX series radios. The zone thing is just a user interface, doesn't really impact the scan function.