Lscott Posted May 24, 2021 Report Posted May 24, 2021 I just picked up an old Kenwood TH-79A really cheap at a local swap the other weekend. After getting the documentation in pdf format off the Internet I saw it has a cross band repeater function built in. This is NOT the same as cross band operation, but a true repeater operating V/U or U/V. I've experimented a bit using a cheap controller, 2 HT's and a diplexer but was looking for maybe something a bit more simplistic. What current production hand held, not mobile, radios have this feature? I found the Retevis RT23 claims to have it and is fairly cheap as CCR's go. I'm not interested in issues concerning duty cycle. Just whether the radio has the basic functionality and how well it works. Quote
kidphc Posted May 24, 2021 Report Posted May 24, 2021 Not many handhelds that I know of with crossband repeat. Almost all the ones that I know of are higher end mobile units not ht.Most of the hams I know will only use it when walking from their truck/car to get some extra range. Say walking down the hill but trying to hit the repeater on the otherside.Personally, I found it tiresome throwing out the call sign with the mention I am cross band repeating and what frequencies. But eh I am lazy.Really only i know of capable is the Yaesu Ft51r. Not sure if even hts with true duplex are capable nowadays.Sent from my SM-G975U using Tapatalk Quote
tweiss3 Posted May 24, 2021 Report Posted May 24, 2021 I'm unaware of any HTs that do crossband repeat, not sure what good 5W of cross band repeat would be, especially since most cross band repeat transceivers cut the power in half while in use. DX Engineering lists 0 HTs with crossband repeat, there are 5 mobile transceivers: IC-2730A, IC-5100A-D, FTm-400XDR, TM-710G & DR-735T. I know the Anytone D578 can as well. Quote
Lscott Posted May 24, 2021 Author Report Posted May 24, 2021 That's the other issue with cross band repeat operation, the ID problem. I don't know of any radios that have the ability to TX the call sign as required when TX'ing from the repeater to the user's radio. The repeater's TX has to self ID on the Ham bands. My interest is something I can slap together quick. For example using a x-band radio on a balloon or kite for field day. Quote
Lscott Posted May 24, 2021 Author Report Posted May 24, 2021 2 minutes ago, tweiss3 said: I'm unaware of any HTs that do crossband repeat, not sure what good 5W of cross band repeat would be, especially since most cross band repeat transceivers cut the power in half while in use. DX Engineering lists 0 HTs with crossband repeat, there are 5 mobile transceivers: IC-2730A, IC-5100A-D, FTm-400XDR, TM-710G & DR-735T. I know the Anytone D578 can as well. This one claims it has the function if it really works. https://www.retevis.com/RT23-Cross-band-Repeater-HAM-Radio Quote
kidphc Posted May 24, 2021 Report Posted May 24, 2021 This one claims it has the function if it really works. https://www.retevis.com/RT23-Cross-band-Repeater-HAM-RadioSo does the Kydera dr-880 uv. 5 watts probably not as effective for crossband repeat but notice the current options are basically Chinese.Any reason an ht and not a mobile unit. Just curious as to the use case.I do have a friend that his house acts like a Faraday cage. So he bought a kenwood 71a to cross band to hit repeaters with his handheld in the house (when cooking during nets). He choose that one because of the autoid function on crossband repeat.Sent from my SM-G975U using Tapatalk WRPC505 1 Quote
wayoverthere Posted May 24, 2021 Report Posted May 24, 2021 2 hours ago, kidphc said: So does the Kydera dr-880 uv. 5 watts probably not as effective for crossband repeat but notice the current options are basically Chinese. Any reason an ht and not a mobile unit. Just curious as to the use case. I do have a friend that his house acts like a Faraday cage. So he bought a kenwood 71a to cross band to hit repeaters with his handheld in the house (when cooking during nets). He choose that one because of the autoid function on crossband repeat. Sent from my SM-G975U using Tapatalk I still have some setup to do with mine, but I'm working out something similar with my icom base. I can get good signal from the repeaters with the ht, but not get out strong enough to open them consistently Planning to set the codes on the base so I transmit ht to base and it retransmits crossband, (since both I generally use have vhf and uhf linked). However, through codes and/or squelch, I'll set it so the base isn't transmitting back to the ht, so I think I'm okay without autoid as the only transmits will be carrying mine going out carrying my call Quote
Lscott Posted May 24, 2021 Author Report Posted May 24, 2021 2 minutes ago, wayoverthere said: I still have some setup to do with mine, but I'm working out something similar with my icom base. I can get good signal from the repeaters with the ht, but not get out strong enough to open them consistently Planning to set the codes on the base so I transmit ht to base and it retransmits crossband, (since both I generally use have vhf and uhf linked). However, through codes and/or squelch, I'll set it so the base isn't transmitting back to the ht, so I think I'm okay without autoid as the only transmits will be carrying mine going out carrying my call That's what I tried with my FT847. I used it in the satellite mode half duplex. The HT would TX to the base radio which x-banded to the local repeater. The HT would then RX the repeater's output directly. No issue with worrying about the ID requirement since I always went from the HT to the base so when I ID'd the base would of course be ID'd as well. The part with the HT which has to operate split band, TX on one band then RX on the other. My big disappointment was the Kenwood TH-D74A. You can't program any of the memory channels that way. The TX and RX frequencies have to be on the same band. Since it does have two VFOs, RX sections, it can still be setup to sort of work that way but it's a lot more of a hassle. It's one of the reasons I still keep my ancient TH-G71A around and several CCR's. That radio is very easy to program for split band operation. Quote
wayoverthere Posted May 24, 2021 Report Posted May 24, 2021 40 minutes ago, Lscott said: That's what I tried with my FT847. I used it in the satellite mode half duplex. The HT would TX to the base radio which x-banded to the local repeater. The HT would then RX the repeater's output directly. No issue with worrying about the ID requirement since I always went from the HT to the base so when I ID'd the base would of course be ID'd as well. The part with the HT which has to operate split band, TX on one band then RX on the other. My big disappointment was the Kenwood TH-D74A. You can't program any of the memory channels that way. The TX and RX frequencies have to be on the same band. Since it does have two VFOs, RX sections, it can still be setup to sort of work that way but it's a lot more of a hassle. It's one of the reasons I still keep my ancient TH-G71A around and several CCR's. That radio is very easy to program for split band operation. Yeah, I think my use case makes it easier being linked repeaters...all my HTs are UHF only except the baofengs, so I listen and transmit to the base on the UHF side, and the base transmits out on vhf. Been testing with a baofeng, but once I have it all set, I'll program the channels into the one of better radios. On topic, it would seem like a lot of work to go through for the power a ht offers, except in a pinch. Quote
tweiss3 Posted May 25, 2021 Report Posted May 25, 2021 I just use a Raspberry Pi 4 and built an allstar simplex node, it can dial to any other repeater or node on allstar, and I get coverage for the whole house. https://hamprojects.info/shari-pihat/ I have a hotspot for DMR, one for D-Star and my SHARI Allstar node. Quote
mbrun Posted May 25, 2021 Report Posted May 25, 2021 Wouxun KG-UV9P and KG-UV8H both have built-in cross-band repeater function. I own both of them.MichaelWRHS965KE8PLM Quote
Edmo01 Posted May 25, 2021 Report Posted May 25, 2021 BLUF: I’m not familiar with any HTs which can crossband repeat... However, I use the crossband repeat feature quite often on my Yaesu FTM-400 mobile. When out hiking or hunting in areas which are beyond my HT’s ability to hit a repeater, I can still have emergency communications via my vehicle’s FTM-400 in crossband mode. If I park my vehicle on a hill or ridge I can extend that range even more. This is especially comforting when I’m in areas with spotty cell phone coverage. Edmo Quote
AdmiralCochrane Posted May 26, 2021 Report Posted May 26, 2021 TYT TH9800 mobile does crossband repeat as well. Probably a dozen more if you look hard Quote
Lscott Posted May 26, 2021 Author Report Posted May 26, 2021 On 5/24/2021 at 9:32 PM, mbrun said: Wouxun KG-UV9P and KG-UV8H both have built-in cross-band repeater function. I own both of them. Michael WRHS965 KE8PLM Interesting. I have a KG-UVD1P somebody at a swap gave me for free. I never looked at it. I’ll have to see by any chance it has x-band repeat. Quote
Lscott Posted May 26, 2021 Author Report Posted May 26, 2021 On 5/24/2021 at 5:49 PM, wayoverthere said: On topic, it would seem like a lot of work to go through for the power a ht offers, except in a pinch. I’m just looking for something quick, easy and cheap to experiment with. The power isn’t an issue at VHF/UHF as much as antenna height. People work some of the LEO FM sats with an HT working into a small Yagi for example. Quote
wayoverthere Posted May 26, 2021 Report Posted May 26, 2021 24 minutes ago, Lscott said: I’m just looking for something quick, easy and cheap to experiment with. The power isn’t an issue at VHF/UHF as much as antenna height. People work some of the LEO FM sats with an HT working into a small Yagi for example. Fair point. I seriously consider grabbing one of those simplex repeater boxes, mainly for experimentation. Quote
Lscott Posted May 26, 2021 Author Report Posted May 26, 2021 10 hours ago, wayoverthere said: Fair point. I seriously consider grabbing one of those simplex repeater boxes, mainly for experimentation. I picked up one of those simple full duplex repeater controllers where you plug in two HT's with the antenna ports cabled into a dual band diplexer. The controller has a built in battery but no ID function. I got a diplexer from MFJ that claims 60db of isolation between the VHF/UHF ports. Most do no more to 40 to 50 db. You really need to read the spec's on these things before spending your money on one. The cheap Chinese cavity notchplexers only claim 70+ db isolation between the TX and RX ports as it is for an in-band repeater. The less isolation you have the lower the TX power allowed to reduce desense. Some cases I've read where there was desense the TX power was reduced, not an intuitive thing to do without understanding how the system works. Quote
MichaelLAX Posted August 25, 2021 Report Posted August 25, 2021 On 5/24/2021 at 10:21 AM, Lscott said: I just picked up an old Kenwood TH-79A really cheap at a local swap the other weekend. After getting the documentation in pdf format off the Internet I saw it has a cross band repeater function built in. This is NOT the same as cross band operation, but a true repeater operating V/U or U/V. I've experimented a bit using a cheap controller, 2 HT's and a diplexer but was looking for maybe something a bit more simplistic... I have two TH-79A's but one of them is dead (as well as two TH-22s). Did you buy two 79s at the swap meet or connect it to something else? Quote
Lscott Posted August 26, 2021 Author Report Posted August 26, 2021 10 hours ago, MichaelLAX said: I have two TH-79A's but one of them is dead (as well as two TH-22s). Did you buy two 79s at the swap meet or connect it to something else? I only got one with a speaker microphone, battery pack (the lower power 6VDC one), case for expendable batteries, antennas and charger. All for $15 with original documentation and box. The radio looked like it was treated well, minimal scuffs and scratches and seemed to work when he showed it to me. So far I haven’t done anything with it yet. It looked like such a good deal for the price I couldn’t resist. The guy was selling it because he went with a newer analog/digital radio and had no use for it any longer. Quote
MichaelLAX Posted August 26, 2021 Report Posted August 26, 2021 They were SO ahead of their time; I hate to sell mine for peanuts: So everything is in one box! You have the hand speaker mic with volume control; mine does not have the control, but I use mine with my Baofeng UV-5x3 Tri-band (144, 220, 440) in the shack. I do not recognize the 12v charger; mine had a 120v AC wall wort that would charge the attached battery, but I also had the desktop dual charger/fast charger. The expendable battery pack should only be used with alkaline 1.5v AAs and not 1.2v rechargeables. I see an extra telescoping antenna, but not sure if it is dual-band. I always loved my telescoping 5/8 wave for 2 meters (1/4 wave when not telescoped) but it was a long doozy! Would really increase the range. These radios could "clone" each other over the air, so that all channels would be duplicated. I believe RT sells software for this model, but I never purchased it; just inputted everything by hand then cloned my other TH-22a from the other one. The battery packs were originally Nickel Cadmium, but I had mine rebuilt into Nickel Metal Hydride. Then a Lithium-Ion pack became available so I purchased one of these (with its own charger wort), too. There are other battery packs that will give you either longer time or higher power (PB33 and PB34). I also have the headset for VOX use when I bicycle-mobiled in the 1990s. Depending upon the condition of the battery pack, this will do you well for when you just need analog simplex/repeater for 144/440 use and the price is right! Check eBay for: newly manufactured battery packs and 12v battery replacement (that will actually run the unit while in the car), but they will easily cost more than the whole kit and kobuttle! hahaha Quote
Lscott Posted August 26, 2021 Author Report Posted August 26, 2021 The charger is for mobile use. I have several of these. They work with multiple Kenwood Ham HT’s. I use this with a fanny pack carrying a lithium iron phosphate pack cabled to a matching socket for extended run time. The radio I used for years, and the very first one I purchased new, when I first got licensed about 20 plus years ago was a Kenwood TH-G71A dual band. I still have it, serviced a couple of times over the years due to a failing volume control. I recently picked up a used one at a swap in very good condition for $45 as a “spare”. My original one I did the MARS/CAP mod on it years ago. The used one I got I left unmodified. I also have a collection of speaker mics, head sets etc. So far the best for walking around and monitoring is the “D-ring” ear speaker with the lapel PPT/mic combo. I use that when I’m out at the mall waking around with the TK-3170 hanging on the belt under a long loose fitting shirt to hide the radio. I run the cable up under the shirt. The only thing you see is the ear mounted speaker. Nobody even bothers to look or stare, including the mall security cop, who I monitor all the time. Likely think it’s just some kind of cellphone accessory. Quote
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