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I recently purchased an Icom 730 HF radio. This is my first HF rig evn
though I have had my Extra class license for about 2 years now. I noticed on the Icom web page that there are several preventative maintence tasks that they recommend performing on the IC-730 due to the age of these rigs. I am looking for anyone that may have performed these tasks on the IC-730 that might be able to give me a basis walk-through of how I need to go about taking the panels off the radio to gain access to the RF unit in the radio. Here is what is listed on the Icom web page that they reccomend doing to the radio: 1.) On the RF unit, resolder the J2 and J3 connectors. Due to the relatively thick coax cables on the connectors, these solder joints tend to crack with age and cause intermittent transmit and receive problems. -------------------------------------------------------------------------- 2.) Make sure the receiver preamp works. If inoperative, replace relay RL1 on the RF unit. Install the factory update to prevent relay failure. -------------------------------------------------------------------------- 3.) Check transistor Q5 on the RF unit. If it is a 2SC945Q, replace it with the improved 2SC2878B to prevent spurious output from the transmitter and failure of the driver transistors. If Q5 is a type 1636, it doesn't need to be replaced. -------------------------------------------------------------------------- 4.) Clean the RIT pot and switch with tuner cleaner. These controls are usually noisy and erratic, making the RIT hard to use. -------------------------------------------------------------------------- 5.) Tighten the chrome-plated PC board mounting screws. The screws and spacers tend to come loose if the radio is used in a high-vibration, mobile environment. Don't forget to tighten the screws on the logic and IF units located beneath the main unit. -------------------------------------------------------------------------- 6.) Check the bandwidth coupler for proper tightness. Tighten as needed. I'm sure the first step of re-soldering the J2 and J3 connectors on the RF unit I can probably handle if all this involves is desoldering the connectors and resoldering them. I'm not so much concerned about the receiver preamp working, but does anyone know if Icom still stocks parts for the Icom 730? The third step reccomends swapping out the Q5 transistor on the RF unit if it is a 2SC945Q transistor and replacing it with a 2SC2878B transistor to prevent spurious output from the transmitter and failure of the driver transistors. How hard would it be to replace this transistor? I would assume it would involve desoldering the transistor and replacing it with the new transistor. Would I just need to get a 2SC2878B transistor and some heat sink compond to replace this transistor? Where would get the 2SC2878B transitor? Can I order one for Mouser, or would this have to be ordered directly from Icom? Step 4 involves cleaning the RIT pot with some tuner cleaner, probably the easiest step. How do I locate the RIT borad to clean the pots? I would assume here too that all I need to do is to spray a shot of contact cleaner in the holes of the pot and switch on the RIT unit? Step 5 reccomends tightening all of the screws on the PC board. Hopefully I can handle this step if I can get access to all of the srews to tighten them. Step 6 reccomend checking the bandwith coupler for proper tightness and retightening it if needed. Where is the bandwidth coupler located inside the radio? What tools would I need to tighten it? I thought I would post these questions on the newsgroups to see if anyone that is a little more technical-minded than me could walk me through performing these tasks. I have downloaded an instruction manual and service manual for the IC-730, but I thought maybe someone who might have a 730 and has performed these tasks could tell me how do them a little easier. The last thing I want to do is screw up a good radio. Thanks for reading my long post. Please e-mail me if anyone can help me out with this. Thanks! 73, Mike KU4UV Lexington, KY. |
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Icom 730 Preventative Maintenance Questions | Equipment | |||
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Icom 730 Preventative Maintenance Questions | Homebrew | |||
Icom 730 Preventative Maintenance Questions | Equipment | |||
Icom 730 preventative maintenance question | Equipment |