tweiss3

I just looked up this license, and saw they got 100W approved for the repeater. Interesting.

Yes, it is software based, but I'm not sure you can select the frequencies you would be using in the hops.

In for answers. It would be nice to find something reasonably priced and halfway decent.

Alright, so yours is closer to the band edge than the other one. Specifications indicate operating temperature range to top out at 60 degrees Celsius (140F). His does exceed that, however, I believe they are designed with a 5/10/85 duty cycle, so I'm not sure its a fair comparison. I don't think his is operating abnormally, but it would be worth the time to crack open the radio and see if a heat sync jiggled loose. Also, wouldn't be a bad idea to hook up a meter and see power draw. If he is spiking a power draw, it would be cause to check out the insides.

I have a handful of questions, because this may be related to a conversation I had two weekends ago when I had a handful of radio's and my repeater on a friend's bench for their final checks before being put into service. marcspaz - which split is your XTL? 380-470 or 450-520? What frequency was your test done on? Ham or GMRS? OffroaderX - which split is your XTL? 380-470 or 450-520? What frequency was your test done on? I am assuming GMRS? The reason I ask is he runs TK-890H (450-480) which can be tuned down to the ham bands. He was finding he would burn one up every 6-8 months even when turned down to low power. He found that, even on the edge of the band (such as in the 380-470 split radio) that the efficiency of the final drops off terribly. While some of that wasted energy can be a fan, the control head, etc, most of it is wasted in heat (what you may be experiencing). He then added a large copper heat sync to each PA and the TX VCO, and hasn't had in issue in 5+ years. Without the copper heat sync, the power draw was indicating a roughly 20% efficiency, and after the cooling mods, he was able to tune them to get 45%+ efficiency. We plugged in my TK-8150 and checked the power output in GMRS, was 43W at high power. We then checked the current draw, and with this inline (Amazon) was seeing a 82W draw giving it a 52% efficiency, which is actually pretty good. The point being, the comparison in temperatures between units should consider bandsplit and frequency. Besides the fact that OffroaderX seems to have improved his situation with active airflow cooling, it might be worth the time to open the case and attach a chunk of copper or aluminum to the PA with some thermal compound.

Comet GP6NC is listed for GMRS & MURS, but out of curiosity I swept it last night and it is pretty decent on the 2m ham band. On 70cm ham, its over 2.1 across the board. 3 of 4 isn't too bad. Below is the 2m sweep from 120MHz to 160MHz.

I don't know. I've heard of stories where Texas ran an out of state plate (MN I think) and ran it incorrectly, and it came back to a guy with warrants for armed robbery. Of course, there was a small number prefix on the plate that wasn't used when they ran it, and after a felony stop and some checking everyone laughed and went on their separate ways. Seeing some other things on youtube, CA not running their own vanity/ham plates correctly isn't that far fetched.

Makes sense to me. It appears that the Quantars have more shielding to them though. Probably why they can be stacked 10 high in a big system and not interfere with each other.

This may be the case, I have no personal experience with this specific repeater, but when my Kenwood was on the bench, the second it flipped into service mode, and the oscillator was turned on, all radios on that frequency in the room picked up the carrier, even without the PA being on.

This sounds like classic desense, the HT in the room used to key up the repeater overpowers what the receiving handheld gets, and you hear nothing. If you could get the two HTs apart by 20' or more, try it again.

Yes, like microwave, except you don't need a license, they are designed as network extenders, except they can go miles and miles.

I think you have two options for RF linking. Though you do mention that LOS is troublesome for some RX sites, but you can do GMRS linking via simplex, but then you fall under the definition of fixed station and are limited to 15 watts. The second option would be IP linking over RF (using commercial dishes with type acceptance) but that is 100% LOS driven.

I think that all the multi-site multi-receive systems (ham, not commercial) around here are linked via RF. You could do IP link, but use 5GHz Ubiquity dishes to link, instead of public ISP. If I knew of a successful one to reference, I would send you that direction. The simulcast/statewide systems typically have fiber connections, GPS sync, high stability XO and plenty of other things going on. It is also a bit more simple since they are digital trunking as well, I would think analog could be significantly more complicated. You could try reaching out to the guys of the big F2 repeater system, I think it's RF linked, but they have 17 receive sites online at the moment, they should be of some help.

I have LiFePo batteries, and they have been worth every penny. I thought of going solar, but just one of my LiFePo batteries will run the IC-705 for just over 48 hours at a continuous 50/50 duty cycle. I sized it for running full FieldDay on a single batter charge. I figure if there is an emergency situation, and if I can't make that work along with the other handhelds, batteries and cars, then there is a lot more problems we are about to have.

Exactly, and with a high profile site, can provide 17+ additional miles of usable range (that goes for any digital FM mode).

Hardline, like Heilax.

Yea, I run the 2/70B and it is very very tall, but at this point I'm not switching it back out for the 2/70SH. I will go back to the 2/70SH when I swap trucks and go permanent mount. I don't notice a ton of picket fencing on my side though, some say it happens when I'm in the valley, which makes sense, but its still fully copyable.

Everyone has an opinion on what is worth the effort, lightening, etc.... Keep in mind, there is a standard, the National Electrical Code, as well as the possibility of local building codes. I would recommend you start there as the minimum standard, which isn't too difficult or expensive to achieve. Also keep in the back of your head, should you decided to do an install that is not compliant with the code, and something does happen, insurances and/or code officials can make your life a living nightmare.

Do you have all all ports of the duplexer terminated? Never forget to place a dummy load or another radio on the unused port (hi/low), otherwise the duplexer creates and unbalanced system and won't give you proper answers.

You can get pretty darn close (much closer than it is now) with a NanoVNA, a few jumper cables and two dummy loads.

Other than the swap of a memory chip on the board, the rest is all software based changes. I highly doubt they changed anything else, there actually was only a memory change between the 868 and the 878, and the plus only meant they included the Bluetooth board. I use bluetooth quite often. With the Motorola gear, I use it with the PMLN7851A, which looks just like a standard hands free earpiece for your phone. On the Kenwood stuff, I use BT for wireless programming, its quicker than with the cable. The external PTT required on the 878 was annoying as well.