Radioguy7268

Look for a used Vertex, Kenwood, or Motorola commercial repeater. You could get something like an MTR2000 that's rated for 100% duty cycle at 100 watts (it will do 50 like a breeze) - and still spend less than trying to get 2 Wouxun mobiles strapped together. Most sellers will program and set up the repeater, and give it a warranty as well.

I think you might have meant to say "relegated" to the dustbin of history, but over regulation will get you to the same place

15 to 20 watts. Don't sweat, it will still be 3x better than a portable.

Yes, a genuine kit would include the cables with the correct orientation tabs. But, the really cheap $10 "repeater maker" cable kits sold on Ebay have no orientation tabs, and can be plugged in either way. I have also seen people totally jam in the correct cables upside down, because they were convinced that the tab orientation was incorrect - since it didn't match their old MaxTrac. They never even noticed that the M1225 dust cover has a diagram molded into it showing the correct orientation.

It's because GMRS licenses are tied to an individual, not to a location. You could be a GMRS License holder in one state, and then have a repeater located in another state, and the FCC would have no idea where your repeater is located. You could also be the License holder, and your sister who lives 2 states away could be the actual user, or her kids. There's sometimes little correlation between the License, the user, and the location with GMRS. If you do want to find out who your local GMRS peeps might be, then yeah just search for ZA within your town/zipcode. Please realize that many of the License names listed might not be actively using GMRS radios, and would probably rather NOT be contacted.

Full disclosure - I've never had a Retevis repeater on the bench to test it out. Judging by the price point (and the design of their portables) it's probably based on a simple Direct Conversion receiver, which are sensitive, but prone to overload. I'd agree that for a simple "quick and dirty" low elevation repeater, it probably does the job for a majority of users looking for their own specific solution. The Retevis is at least less than the cost of a good used MTR2000. I'd really ask anyone looking at a Bridgecom or building their own Woxoun repeater out of 2 mobiles to stop and check out the alternatives available. You really can end up with more for less, if you consider used Part 90 gear. And, that used Part 90 stuff has a resale value when you're done with it. Something you won't really see with used Bridgecom equipment.

Creating a repeater out of two radios that meet Part 95 does not mean you've got a Type Accepted Part 95 repeater. As mentioned, it is also quite expensive compared to the (IMHO better) alternatives. Vertex. Motorola. Kenwood. They all made good Part 90 repeaters. Some will put out at least 50 watts at a 100% duty cycle. Used units are available that will outperform a Bridgecom - and do it at a better price point. They also have a history of performance, along with available support (that you will probably never need).

Yup, no WiFi - no Bluetooth, and lacking GPS. 3 things that might be important if you built a fleet around advanced feature stuff like Indoor Location or Enhanced GPS. Those chips are also missing now in the XPR3500e/3300e portables. The good news is that by dropping those features, they reduced the lead time to months instead of years. A recent customer order for some XPR radios shows a January 2023 expected ship date. The good news is that by getting the order in now, I have already beat the next 2 expected price increases.

I laughed when I read that. The Gman does NOT spend big money on his radios. Most of his Motorola gear was acquired at prices well below dealer cost. I'd venture to say that every Moto radio he owns could be sold today at a profit. Not sure many CCR owners could say the same. But, you're right about receivers.

Make sure to terminate any un-used port on the combiner star if you remove the cable and/or isolator from use. I think you're going to find that one or more of the isolators you were using will no longer tune. Measured forward loss through any specific dual isolator when measured on its own should be less than 1 dB when properly tuned. EMR has a ton of white papers online concerning combiners/filters/isolators, antennas, and duplexers. Lots of good info there, even if I never liked their square cans. EMR Corp tech papers I'd suggest reading "The care & Feeding of the RF Isolator" on that link if you haven't already. It will set you straight with what's going on. EMR also did a writeup on how to Field Tune a Dual Isolator: Field Tuning a Dual Isolator

As everybody told you in the other forum, the spacing was too close. As for the cable length, yes you need to be fairly precise, and your measurements need to take the connector length into consideration. I can tell you that TX/RX Bird used to stock cables in 1/8" increments, and they would sell them to you at reasonably inflated pricing, but to me it was still cheaper than the time spent to make your own. Not sure if they still do that. There's a reason I know how close they'll go. I was down this road with VHF combiners 20 years back, trying to make existing stuff work at spacing under spec. Don't try to jam 100 watts into the combiner, don't expect miracles, and pay attention to the size of the dummy loads you're dumping the isolators into. You will need something rated for more than 5 or 10 watts.

Years back there was an interesting write up that a club did - where since they were going to have to sidemount their transmit antenna - they ended up going with a 3 sector antenna system using stacked 3dB yagi antennas, and used a phased harness to make it all work. At least, that's how I remember it, and now I can't find it online with a weak search attempt. I do remember that it was an interesting article, wish I could find it again.

Since you're still trying to do the impossible - it's not surprising that you're having trouble. Pretty good bet that 1 or more of the isolators is burned up. There's a max amount of reflected power that an isolator will handle. Think of what you're doing when you place another transmitter right next door on a frequency too close for the design spec. Think what happens once that 3rd transmitter keys up... it's adding to the problem, and it's not that much further away. Loss on a typical bandpass single cavity/dual isolator combiner setup should be 1.5 dB per channel.

If you've got a 5 port "star" (4 transmitters feeding into 1 antenna) - then the 4 harness legs coming from each tuned transmitter cavity would typically be an odd wavelength ( 1/4, 3/4) of the frequency you're using. I question the spacing you're using, as typically if you get that tight on frequency (less than 50 KHz) spacing with a combiner, you will need a hybrid/ferrite combiner - and 10 dB of loss is typical of those. 250 KHz would be more typical of the absolute minimum spacing for a bandpass cavity design with a dual stage isolator for each channel, not 25 KHz. http://www.repeater-builder.com/antenna/db/pdfs/db-about-combiners.pdf

For anyone planning to implement MDC signaling, you should investigate the use of DOS (Data Operated Squelch) and PTT Sidetone. I'd recommend only using it in a group if everyone on the repeater is using MDC, and everyone agrees on the setup parameters. If properly done, the users on the system will not hear the MDC squawk, and every radio on the system can ID other users. MDC can also be used for selective calling, radio alerts, and Status updates. It's a pain to set up if you're using multiple radio models across different manufacturers. DOS will silence the MDC turkey call noise (either pre, post, or both) for users that have it active - and a PTT sidetone can be useful to remind the user to pause for a moment until the MDC pre-burst is sent. Set the PTT sidetone to something less than obnoxious if you're using it. Whackers like MODAT, MDC and PTT Sidetone - even when they're not actually using MDC for any signaling benefit. They just think extra noises sound cool & they heard all those noises on their Bearcat Scanner - so they think that the radio users must be hearing those noises too. Well designed radio systems don't annoy their actual users with squawks and obnoxious beeps.

PL stands for "Private Line" - which was Motorola's term for ctcss (continuous tone coded signalling squelch). It's a sub-audible tone that's generally between 80 and 300 Hertz. It seems you have already figured out how to plug that in. DPL is Digital Private line - which most manufactures call DCS - Digital Coded Squelch. I'm not familiar with the Wouxun product line, but other people here are, and I'm sure someone will tell you how to plug that DPL code into your radio in order to access the repeater. If the repeater you are planning to use has PL on the one frequency, and DPL for the other (probably higher) frequency - that's termed a "split tone". Not all radios are capable of using split tones - but you might be in luck with the KG-935g.

A good "courtesy tone" is generated by the repeater, and should be at least 10-12 dB down in volume from the voice audio. In other words, the courtesy tone is well below the user's voice level. It should not be shrill or harsh. It's more of a clue than a control signal... A radio that generates its own Roger Beep upon release of the PTT should be avoided IMHO. I haven't played around with enough CCR's to know what's available in the programming, but the tones I have heard over the air on GMRS usually seem to be on the edge of obnoxious.

GMRS rules used to specifically mention that any Non-English conversations still needed to ID in English (or CWID). I'm not sure if the newer version of the rules still says that, but I can tell you that my family regularly uses non-English on the repeater, and allows the CWID to take care of identifying. I don't really care if A$$C10WN gets upset about that.

The trouble with a Carrier Squelch repeater is that it will repeat literally everything it hears. There's no real control, and if you're high up, you'll hear the world, including stuff that you really don't want to repeat. If you've got any other co-channel user close by, your repeater will be keyed every time one of their mobiles is transmitting. Not ideal, not even close to useful, and pretty much guaranteed to be a pain to your neighboring system. I don't see anything in the rules that says you have to run PL, but the FCC does say you're supposed to avoid interference and monitor before transmitting.

The biggest issue with your plan (as I see it) would be actually acquiring the equipment in today's supply shortage world. DLR (and DTR) 900 MHz Frequency Hopping Spread Spectrum radios are great for indoor coverage. If you're looking for some Rental Agreement boilerplate, dial up one of the major players and tell them you're interested in renting 10 or 20 radios. See what they send you (nobody says you've got to sign it & agree to the rental!) As someone who has a fleet of UHF and VHF rentals, I can tell you that the biggest issues are #1 - dealing with someone who has actual spending authority. #2 - getting ALL the radios back after completion of the rentals. #3 - Defining the cost of replacement up front, so that there's a responsible User in charge who will represent your interests in having the radios returned in good shape. You should also consider Gang Chargers as a necessary part of the equipment list. You'll never untangle all the charger cords on single unit desktop chargers if you include them with a stack of rentals.

Re-reading your post, it seems you're asking if we can identify the actual noise that you're experiencing, rather than the effect. I can't hear it well enough to discern what it is. There does seem to be some mixing involved. Are you friends with anyone who has a spectrum analyzer? Are you able to get an RSSI reading of the interfering signal? Does it come and go? or is it always there on your receive frequency whenever your system is idle? If it's constant, you can be almost certain that it's another transmitter on a totally different frequency that's mixing with something else nearby to create what you're hearing. Search up "2nd order intermod" to get an idea of what could be going on. Direction Finding could also be useful to pinpoint the area where the signal is coming from.

Yes - the FM Capture effect. Basically, in FM the stronger signal will win. Once the stronger FM modulated signal is about +6dB or better (stronger) than the interfering or weaker signal - you won't notice that there's another signal present, or your ear might be able to discern a slight very slight warble/wobble in the background if the interference is fluctuating right around that 6dB level. This also gets into the reason why Pre-emphasis/De-emphasis has become the standard for FM radio transmission. You can read entire books and articles dedicated to the study of FM capture. It was one of the reasons that Armstrong pushed FM as his preferred modulation method. Compared to AM - it certainly did have less static. Armstrong pushes "staticless FM" technology - Free from interference...

The rules don't say that you can't use it - but I'm not aware of any Motorola radio that's type accepted for Part 95 that has MDC signalling. "Legal" has lots of angles you can view it from. There are other brands that now offer MDC signalling.Vertex, Icom, and Kenwood all have certain models that offer it. It may not be fully compatible with all features in the MDC1200 Motorola world, but they've got it. I'm not actually sure if Motorola patents expired, or if they just decided to license it to other manufacturers at a more reasonable cost.

I must have missed the part where a willing buyer and a willing seller are involved in a transaction that becomes a rip-off. If someone is willing to buy something that's a price 3 times above what it 'normally' sells for - then that person is signalling to the market that there is a shortage of the product, and that there is an opportunity awaiting those who can fill the gap. That's economics 101. People make noise about price gouging and rip-offs. Pricing to the market is what every enterprising businessperson does - or they go out of business. If you're a consumer who pays 3 times the 'normal' price for the product, you either have a compelling reason for buying it, or you're plain nuts. Wait out that temporary price increase if you feel that the market will correct, or search for alternative products that meet your need at a price that's more appealing.

You likely don't have the front mic HUB grounded (ie: the radio thinks it is off hook). Been too long since I was into the MCS2k software, but there should be an "ignore HUB" setting or similar tick box that would work. Or, if your mic jack is open, slap a palm mic in that has a hang up clip attached.