[Repeater-Builder] Zetron Model 66
I got one from the Pager equipment Junk. Any use for this in a amateur repeater site? Can we convert it into a Rpt controller for VHF? Peter
[Repeater-Builder] Do you know Any Kenwood TKR 720 in Junk? to salvage MPC......
Further to my earlier posting, I tried to locate the Microprocessor Chip for the TKR 720- IC uPD 75104G-604-1B, from all known sources in US to Hongkong! Pacparts and Kenwood HK clearly said it is out of production and no more available, AND no substitutes!!. Two requests: No.1. Can any one help me with a junk collected Display board with the above IC? D75104G-J99 (NEC) in TKB-720 can also be utilized. OR any other source for a salvaging of this chip? No2. All other PCBs and the PSU are made OK in this Amateur VHF repeater, It delivers 50W! Any modifications? or can we separate the RX and TX circuits and add some other repeater controller to eliminate the above IC. It is so sad to discard a beautiful equipment just on need of one chip!! Peter
[Repeater-Builder] KENWOOD TKR 720 REPEATER REPAIR- HELP
Last week I received a Kenwood TKR 720 VHF HAM band repeater for repair. It was traveling all over the country for the last five years to get a proper repair! On this travel it lost many spares, which includes the EEPROM chip (94LC 46)from the IC socket and the shielding covers. Comparing with another TKR 720, I could set right most of the Boards. The earlier experts who tried to remove the various modules from the double sided TX-RX card, taken away few SMD resistors also, may be unnoticed. Two of the 1K resistors were from the RX and TX line, which made the equipment deaf and dumb (=dead)! The front panel also have another 94LC 46 soldered, near the micro controller uPD75104G-604-1B. My present problem is to replace the micro controller which is not functioning,( I replaced it from the other set along with the 94LC46 to confirm the defect!) Can I procure the micro controller from any source and replace it simply by soldering? OR Need a pre-programmed one from the KENWOOD? Very remote chance for us. Can any of our supporters locate one for me on payment? Do we have to replace the nearby 94LC 46 also? How to program it? I have the KPT50 for the EEPROM programming of the TKR 720, but it can only be used for the frequency and other parameters set inside of the KPT 50. Commends are thankfully welcome PETER VU2PJP
[Repeater-Builder] Yaesu / Icom spare parts-source wanted.
Three VHF rigs of mine need spares: Yaesu FT 2500-LCD DISPLAY BROKEN Yaesu FT 2600-LCD display broken Icom ic V 8000 -Transistors 2SK 3074 and 2SK3075 Any help on sourcing these NEW OR OLD, is highly appreciated. PETER VU2PJP
[Repeater-Builder] SPARE PARTS FOR YAESU RADIOS
I am in need of few spare parts for my Yaesu VHF equipments. After the merge to Standard Vertex, our old YAESU dealer is not able to provide me any spare parts. Immediate need is LCD display units for FT 2500 and 2600. Can any of our readers provide me a source, for international purchase? PETER VU2PJP
[Repeater-Builder] Pager antenna-Amateur Band modification II
In response to my earlier posting on the RB few quarries are there, hence I wish give the following for further thought: The antenna is CELWAVE PD340-TP2 with 4 Separate folded dipoles on a big aluminum pipe mast. The connecting harness is routed through the pipe mast. This particular antenna is with 12Mhz bandwidth and tunned for 162-174 MHZ. All the specs. are available in the website . Scaling the dipole elements as per ARRL Antenna handbook are possible. It is made of 10mm rod and the length of the dipole is 80cm., cutting and adding another 5-6 cm in four lengths of the folded dipole (to make the length to 91cm approx), can be done with best craftsman, to bring it tuned to 145.5Mhz. My present concern is with the harness inside the pipe mast. Will it join happily with my modification? or have to modify the harness also? HOW ??? HELP!! PETER VU2PJP
[Repeater-Builder] RPT Antenna trimming -Length to RX or TX freq?
Our new Diamond F22 antenna elements to be trimmed as per the enclosed cutting chart for the 145.650 with -600 shift. What length is best from the cutting chart is in doubt. Whether it should be the length for the Tx freq-145.650 or for 145.050-the Rx? Peter VU2PJP
[Repeater-Builder] Pager Antenna-Possible to convert for 145Mhz?
Recently I got one Celwave antenna from junk market, with 3inch dia., thick long aluminum pipes as mast and many folded dipoles inter connected with thick coax-may be harness. Total length may be more than 20 feet. Heavy flanges and rubber pads in a kit. I am sure our expert supporters can suggest a way to bring this giant to 145MHZ. -for our repeater in the 145.650 with -shift. If-then we can beam our precious 3watt of RF power to most wanted operators far off, avoiding the radiation on to the hillock on the back side of the RPT site. Peter VU2PJP
[Repeater-Builder] TNX-RPT.BLDER! Our RPT now sounds fine NOW!.
Our VHF Repeater-VU2BCM located at a height of 4000feet MSL with a coverage of 200km radius in the plains down, was having so many problems after the shifting to a new QTH nearby. The equipment is an old Yaesu FTR 2410 ( Pl. do not laugh at us!) with 4 cavity Wacom duplexer on 145.650 -ve shift. Whatever be the new generation equipments this one served the HAM community for more than 20 years, as the best and popular repeater, without any major or minor complaints. Never the equipment behaved the wrong way. But after the change of the QTH to 20 feet away, all the Rx sensitivity lost and on weak signal motor boating or machine-gun fire made the installation useless. Then we ventured into probing the RPT builer archives and with the available information, we made one more visit to the site day before Yesterday. We changed the antenna to Diamond F22( earlier it was X510), changed the coax feeder, changed the Repeater to Kenwood TKR 720 ( No ears! Please help us with our other mail on this), Then looked around the Patch cords, all he connections to the duplexer checked. Power at the RPT TX out with Diamond SX 400-> 10Watt.The output to the antenna is measured to 6Watts. All fine but the early problem on weak signal was persisted allover this trials! Finally the suggestion to try a different length of the Patch cords came out and since the problem was with the RX we tried all possible combination lengths. No success. As the last try before close down- changed the TX patch cord-Distant weak station came in with out any gunfire! A small added change in the length created less sensitivity. We made an exact length of the good patch cord and tried that also worked fine. Put the old one-motor boat came back!! A small patch cord in the whole system- which looks fine, tests fine created all the discomfort! We also reduced the RPT TX power to 3Watts!(earlier 10Watts) The standard S meter reading of full scale came down to less 4 points in most of the reports from the users, but no one complained about any access issues- improved the RX sensitivity and audio quality! Hope the above will help others also in sorting issues related with RPT sensitivity. Before looking into the RX, go to the TX path. PETER VU2PJP
[Repeater-Builder] HELP! KENWOOD TKR 720-low Rx sensitivity.
We have a standby Repeater Kenwood TKR 720, whenever we replace this to our old Yaesu FTR 2410 the outer foot prints are lost and no access to weak station even at the lowest power of 15watts. The equipment is very less used. Came to us as a new one. No mods done. How about connecting a separate RX ? Any mods? please help us ... ( TKR 750K2 is different with good ears-we tried) PETER VU2PJP.
[Repeater-Builder] ICOM IC 310/110 2 X REPEATER CONFIG PROBELMS!
My effort to config the simple back to back repeater- using two Icom IC F310 or IC F110 is having a common probelm, for which I appreciate best suggestions from experts. Both of the above series of equipment have provisions for connecting OPC cable assy to convert two of them into a repeater. The other method is to interconnect the COR-PTT, Discr.audio -Discr. input. The horn out option and the EXPTT to be enabled in the programming. In both the cases I am failed to provide the Tone squelch to restrict the access as well as to false triggering from the surrounding noise. I prefer to have the Tone part in both the access and on the transmit signal from the Repeater, same as the Kenwood TKR 750 etc. The programming software indicate provisions for this but I am doing some mistake somewhere, that is what I feel! Or will it get diabled when we enable the horn-out and EXPTT? Peter VU2PJP POB 68, PALAKKAD-INDIA
[Repeater-Builder] KENWOOD TKR 750 Installation and problems-HELP!!
Last week we installed one Kenwood TKR 750 (Type 2)in our nearby airport for the use of the security organisation. The Tx is in 143.95 and Rx is in 148.950. The antenna is Diamond F22 without any trimming (144Mhz). The Repeater delivers 20Watt into the duplexer of local manufacture and 15watts is loded to the F22. SWR >1.1 !! To avoid any local noise, we done the QT/DQT with first tone (67)in the whole fleet (92 handies) and coutesy tone for indetifying the RPT access. The mounting is done at a height of approx 60 feet from the ground on the Fire watch tower in the eastern side of the runway (Runway is East West and on the Southern side of the building) The coverage in the open space is excellent and extends to more than 10km out side the Airport through the surronding thick vegitation of Coconut trees and buildings When we started the coverage test inside the building, the Domestic terminal in the eastern side (approx two kilometersfrom the antenna) gave very good hope. But when we tried in the western part of the same building, lot of blank spots were noticed in the ground floor, in the middle of the building. If you move two feet to this side or other it works fine. Just get out of the building to the to the verenda-59 report. In many areas the the Repeater triggers and clean Courtesy tone is received, but the modulation is very noisy and beyond readability. One suggestion is to shift the antenna to the top of the terminal building itself, which is 5 floors and of thick concrete, with lot of AC ducts. ( The required coverage area will be just five floors below the antenna) Can you suggest solutions for extending the coverage to inside of the building to avoid the blank spots? PETER VU2PJP POBOX 68, PALAKKAD 678 001, KERALA, INDIA. HP: 91-094470 65426
