I spent 17 years as a Signaler in the Australian Army reserve Artillery and used these radios ANPRC 77 a lot gave me goose bumps seeing you use and retrans radios i'd have loved too have a complete set myself oh joy ,even the ANPRC 25 was an alright radio,remember still the differing frequencys for Australian radio stations what memories many thanks.
@Helge Fykse, It is not necessary to use the two handsets, the audio lines of the two PRC-77 are connected accordingly via the long cable. I worked 22 years in this company where these devices were produced as a test field engineer and we have produced thousands of these radios.
I'll try to explain this. The two stations that talk together are located so far apart that they do not get connected. I therefore mount the relay station on a mountain. I can reach both. Then I connect the relay station. Then they can talk well together. This is especially useful if one or both stations have a small portable radio. LA6NCA
It's boring without the KYK-28 AND KY-38 so you could set keys and encrypt in x-mode... Encryption was 128bit undocumented NSA cipher that you can probably crack with a cellphone processor now... The devicee that came after KY-38 used PKI set in ROM so only NSA can key them... KGB likely reversed the silicon and knows the cipher used in KY-38
Nice, Helge! Would have been even more fun if the "end stations" had run with regular 4m and 6m amateur equipment :) AN / PRC-77 has 150 Hz tone squelch. Amateur equipment does not have enough signal level on the tone. I'll see if I can increase the sensitivity of AN / PRC-77
@@LA6NCA If I remember correctly the PRC77 also has "normal/old" noise squelch, as most ham equipment. Was the "old" squelch too unreliable for retransmission?
Hello good night you have the schematic for mounting the cable Retransmission Cable Kit RTC-77/GY or if you could make a video showing how it looks inside the kit so you can play a? Thanks 73 PU1XYZ.
Retransmission Cable Kit is the MK-456, and there are some circuit diagrams on the web. It looks like the ones used by Euro militaries (or perhaps license-built in Europe) carry the "RTC-77/GY' nomenclature, though they appear to be exactly the same thing and do the same job as the MK-456. You'll find the MK-456 retransmission cables fairly frequently on Ebay.
I'll try to explain. The two stations that talk together are located so far apart that they do not get connected. I therefore mount the relay station on a mountain. I can reach both. Then I connect the relay station. Then they can talk well together. This is especially useful if one or both stations have a small portable radio. LA6NCA
Each radio is on a different frequency. Let's call them Radio A and Radio B. Let's say we have two users named Bob and George who live on opposite sides of a mountain and can't talk to each other because the mountain's in the way. We take Radio A and Radio B and put them on the mountain with the cable between them. The cable lets anything received by Radio A go through the cable and get automatically transmitted again by Radio B. And the same in the other direction. Bob on one side of the mountain has his home radio set so he can talk to Radio A on top of the mountain. What he says goes through the cable and gets transmitted again by Radio B - so George on the other side of the mountain with his home radio set to talk to Radio B can hear him. Bob and George can now talk to each other despite the fact they're on different frequencies. They're no longer prevented from talking to each other by the mountain being in the way because each is only talking to a radio on *top* of the mountain. With this setup you can also talk *farther* between stations, because Bob and George's radios just have to talk to a midway point (on the mountain top between them), so both of them could be near the limit of their radio's range so long as they can still talk to the mountaintop radios between them both. Maybe when Bob and George talk to each other directly - they can only have 15 km between one-another before they go out of range. With the mountaintop setup - they can now be 30 km away from each other because they only have to talk to Radio A or Radio B on top of the mountain - and each could be 15 km away from the mountain on either side.
Original batteries are hard to find. I have therefore put power banks for mobile phones into the battery box. A DC-DC converter supplies the radio with 13.8 VDC. Cheap and easy to charge.
