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Hello Stu.

Please allow me to clarify some aspects that are not correct and may cause several problems.?

The negative should always be fused... Always.?? Correct. And don't use the vehicle chassis etc for the negative -- you want a "clean" low resistance connection from the power to radio.? (unless your car has a postive earth.? I don't think there are many of those still around)

Both cables should have a fuse as near as possible of the radio. NO !? Both power wires should go straight to the battery (or power supply at home)? Especially In a vehicle, the fuse should be as near to the battery as possible so that any short in the wiring between battery and radio will be protected and you will not have a melt-down in the cable.? Most mobile radios you buy will normally have only ONE fuse in the positive lead as supplied.

In case of a short inside of the radio that "close" the? circuit by the negative the unit will be protected by the fuse, and not as an direct cable without protection.? Not sure I understand this one.? A short (or high current problem inside the radio) will go through your thick (red power cable and blow the fuse at the battery

Both cables should have a direct connection from the battery to the radio and we should avoid picking it from split sources.? Correct -- avoid sharing the same power wires with anything else

We always should have the radio off when we start the car to avoid drop of voltage and spike of currents. "good practice" correct and that's usually the case, but I probably do it occasionally and never had a problem.

Also the problem of the miss connection of positive and negative is because of the fact that the radio does not have a protection against inverse polarity neither increase of voltage. Once again, probably correct,? but I wouldn't guarantee that I've never done it in the 10 years I've had it.? The on/off circuitry probably shields the rest of the radio if you make a mistake (but don't rely on that !

There is a small mod that adds a diod and a zenner to solve this problem, you can even install it outside of the radio, in a parallel connection from the white plug.? I've not heard of this on the 857, but back in my early days this was often done when we used "ex-buiness" surplus radios re-tuned to the ham bands, which were usually not reverse supply protected.? But you had to use a very low forward resistance diode or you lost over a volt in power to the radio.? Remember that your diode, (and zener) have to be rated at least 20 Amps on full power FM.?

Another note on fuses -- I've noticed several cases when people have lost voltage displayed on the screen, or even had intermittent complete loss of power.? This is often caused by a fuse or fuse-holder that is corroded slightly.? first thing to do is to clean or change the fuse.? Ifr that doesn't work check the fuse holder.

Stu

If you need some further details please let me know.?

73

Rui

A segunda, 1/02/2021, 08:28, Stu Nutt <stunutt@...> escreveu:

First of all, I think you mis-typed the radio model below -- I don't think Yaesu ever made an "837" ?

I've been using an 857 for about 10 years (with various antennas), but not had the Radiowave that you mentioned.

Overall. the radio is pretty indestructible as long as you take a few fairly normal radio precautions.

1. ?Don't get the positive and negative power connections the wrong way round? !? The radio is fused, but if the fuse in the positive (red) wire doesn't blow, I believe there is an internal fuse soldered into the rig which could be a nightmare to replace.
2. If you decide to use it mobile, don't rely on the antenna ground for the negative connection, and don't fuse the negative (black) battery connection as in certain fault situations the current from the car electrics could be routed through the radio -- the starter motor can draw over 100 amps!
3. Antenna -- As I said, I have no experience of the Pathfinder MKI antenna, but it is an end-fed antenna, which normally would have a high impedance on all frequencies except when its length is a half-wave (or multiple of).? Radiowave will have a system included for matching it to other ham bands.? There are a number of ways of doing thus and I don't know which one they use.? However, I have seen reports that it does not work so well on the 80m (called 75m in USA I believe) and 160m bands.? In the case of the 857, it is protected from antenna mis-match (which can destroy the transmitter output stage) by automatically reducing the transmitter power and protecting it.? However, the 857 specification says that it can be operated at up to 1.5 to 1 SWR, but I've found that mine seems to drop the output from about 1.25 to 1.
   
   An SWR meter is always a thing to have with transmitters, and you can buy one for a few tens of dollars.? Having an SWR meter in the? transmitter output will allow you to see a fault that occurs in the antenna or feeder cable, and save you from calling away for a contact because the fault has caused your radio to drop power and nobody can hear you.? If you find that the SWR isn't good enough on the lower bands (and the antenna and feeder seem to be okay) you'll need to buy an "antenna tuner", rated for 100 watts or more, to "match" the antenna system to your radio.
   

?Good luck with your experience on the ham bands and with the 857.? If you ever hear a signal coming from G3OCR in England, please give me a shout and let me know how you are doing ?

Regards,? Stu

On 01/02/2021 02:18 am, Adoni Poledicha via wrote:

Greetings to all,

I got my hands on a FT-357D and I am very concern with making sure I properly get it power up, and running without damaging it in the process.

Although I am a licensed ham radio operator, my experiences are limited to military type radios from HF and up... and have had a long break from the career and operations.

This FT-357D is completely new to me, and considering how great of a radio it is, and irreplaceable, considering it is no longer manufactured and difficult to obtain parts, it is critical that I get the process spot on into setting it up and correctly powering it up.

I have in mind of setting it up as a desk top radio and have obtain a Yaesu DC Power supply model FP-1023, and a LDG YT-100 tuner.

For an antenna, I obtained a Pathfinder MKI power 500w SSB 100w CW by RadioWavz.

Anyone with experience that can assist me in the process of my efforts to getting this rig up on the air, will be greatly appreciated by me.

If there are any resources someplace else for me to look into, that would be of help to.?

Thank you,?

Look forward to your feedback.

All the best,

Adoni

KG5WHC

Sent from mobile device

On Jan 31, 2021, at 7:25 PM, John <ve3kkqve3kkq@...> wrote:

?

Perhaps we 8X7 owners should order a new chip, we may just exhaust the world's supply!!

John

VE7KKQ

On Sun, Jan 31, 2021 at 2:55 PM Theo Marinos <marinos.theo@...> wrote:

This is very hand to know. Thanks for telling us.?

Regards

Theo

VK5IR

On Mon, 1 Feb. 2021, 9:22 am rifkum via , <rifkum=[email protected]> wrote:

Hey group,
Thought I'd share my experience fixing my 857. (Probably 15 years old, always used inside)
In the past year or so whenever I turned on the 857 it would not come back to the way I powered it down.
Typically I would have it in Memory mode (not VFO) and scanning VHF/UHF programmed channels.
When I power it on it would almost always come up to a VFO random frequency and be scanning up or down the freq.
About every 10-20 times on power up it would come up with the display contrast dark, with big digits and when I switched to Memory mode and tried to transmit I would get a TX ERROR.
In this mode I always had to reflash the program from Chirp.

I watched a few youtube videos and found that likely it was the EEPROM memory chip had gone bad.
So I ordered one off digikey. The part is Q1066 on the schematic and it is a 24LC128T-I/SN
Pay attention to the package size I/SN NOT I/SM
It was an easy swap if you are ok with SMT

Reloaded the program from Chirp and it has not failed since.

cheers
Dwight

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First of all, I think you mis-typed the radio model below -- I don't think Yaesu ever made an "837" ?

I've been using an 857 for about 10 years (with various antennas), but not had the Radiowave that you mentioned.

Overall. the radio is pretty indestructible as long as you take a few fairly normal radio precautions.

1. ?Don't get the positive and negative power connections the wrong way round? !? The radio is fused, but if the fuse in the positive (red) wire doesn't blow, I believe there is an internal fuse soldered into the rig which could be a nightmare to replace.
2. If you decide to use it mobile, don't rely on the antenna ground for the negative connection, and don't fuse the negative (black) battery connection as in certain fault situations the current from the car electrics could be routed through the radio -- the starter motor can draw over 100 amps!
3. Antenna -- As I said, I have no experience of the Pathfinder MKI antenna, but it is an end-fed antenna, which normally would have a high impedance on all frequencies except when its length is a half-wave (or multiple of).? Radiowave will have a system included for matching it to other ham bands.? There are a number of ways of doing thus and I don't know which one they use.? However, I have seen reports that it does not work so well on the 80m (called 75m in USA I believe) and 160m bands.? In the case of the 857, it is protected from antenna mis-match (which can destroy the transmitter output stage) by automatically reducing the transmitter power and protecting it.? However, the 857 specification says that it can be operated at up to 1.5 to 1 SWR, but I've found that mine seems to drop the output from about 1.25 to 1.
   
   An SWR meter is always a thing to have with transmitters, and you can buy one for a few tens of dollars.? Having an SWR meter in the? transmitter output will allow you to see a fault that occurs in the antenna or feeder cable, and save you from calling away for a contact because the fault has caused your radio to drop power and nobody can hear you.? If you find that the SWR isn't good enough on the lower bands (and the antenna and feeder seem to be okay) you'll need to buy an "antenna tuner", rated for 100 watts or more, to "match" the antenna system to your radio.
   

?Good luck with your experience on the ham bands and with the 857.? If you ever hear a signal coming from G3OCR in England, please give me a shout and let me know how you are doing ?

Regards,? Stu

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