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Just reporting back:

The rolled up tape idea didn't work for me -- tried many times with two different types of very sticky tape.

However, the hot needle idea worked on the first try!

Thanks!

-Farren

I'm thinking about making a simple rectangular battery tray out of either sheet metal or polycarbonate to go under the radio and attached with the lower cover screws. I know such a design would hold at least six 18650s. A little expansion in suitable direction(s) could easily hold more cells. Battery tabs aren't required if cell holders are used. Just a thought.

Can you send the stl file?

Have a great day!

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From the graphs I've studied it seems like 9.0 volts is more realistic for a 100% discharge, both for the battery and for the radio. On that basis I would consider it to be ideal.

I had a question regarding this 3 cell Li-ION pack with the 3d printed chassis and cover.

With a 12.4V peak, 11V nominal, and 8.25-7.5V cutoff voltage how well does this work with the 817?

Does it allow you to run full power? I did some tests a while back, and the results are a little fuzzy in my head, but I seem to recall that the radio only allowed full power when the internal pack voltage was above something like 11V.

Is this the case? Adjustable? Radio switches to low power at a certain voltage?

Thanks,
Albert

Ok Steve,

I will slicing the .stl files and heat up the printer to try print it. We will see¡­

Petr

I Have The Cells But do not have the space for a 3d printer Its a Shame That we no longer the large base of FT-817/818 users to get a entrepreneur to produce that "KIT", I Sure Would go for at leas 2 units, the $90 Windcamp "solution" is a bit much.?
Best Regards.
Steve AB2ET/4

If anybody want to help with 3D print then I can do it.

73 - Petr, OK1RP
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What could be easier..? ????_?(?¥Ä?)?_?/??

>> You can bridge Q1104 on the top side by connecting 13.8US (3 pins to PA) to TP1084 (emitter of Q1082).

I did this with a wire and the power-up sequence remains the same -- LCD black, relay click on the filter board, powers off.
I'll add something semi-permanent and see what the voltages look like.

b

On Thu, Oct 27, 2022 at 03:03 AM, Bill W1PA wrote:

I put in an ammeter in line with power, and as the rig powers up, it gets to just over 0.5A draw before it shuts off.? As I understand it, the op-amp circuit near the power connector uses the common mode choke as a current sense device and sends a "power off" signal to the CPU to shut things down if it doesn't like what it sees.

This is used on transmit - the limit current would probably be quite high >2A.
I would not expect it to trigger at 0.5A even if it was active during RX as this is within the normal operating current range with volume up.

You can bridge Q1104 on the top side by connecting 13.8US (3 pins to PA) to TP1084 (emitter of Q1082).
Now the radios power will stay on and you can see what the voltages are, and check how much power it is using, and check that voltages (like the main +5) are correctly reaching the front panel.
To turn off, the front panel must be seeing an unexpected level on one of the lines that reach it.
There is not a lot of smarts on the main board - no processors or other digital devices that return anything to the front panel. i.e. it has to be some static level on one of the lines.

I have the ebay aftermarket battery,works fine:

Hi!

Here is a question that I think I know the answer to but here goes - I've a '817ND bought several years back as a 'shack in the box' for use in a small 'domestic' shack. It has never been used "man pack portable" it is fitted with the standard NiMH battery pack just in case..but in practice it was powered almost 100% of the time via an external PSU -? I did cycle the cells from 'fully charged' on a regular basis. This has all been fine and the little box has served me well however the original battery now does not charge to the 'normal' full charge voltage and doesn't hold a charge for long. ?? I have concluded the battery pack has come to end of its useful service life and needs to be replaced.
Since I never use the rig "backpacking" '/p' I think the replacement standard pack is not really worth the outlay - I have the power pole adapter fitted so I can use an external SLAB, or AA Ni-cads or even standard AA cells if I do wnat the '/P' option Are there any known 'gotchas' to this approach ?

73 John G8EWG

I've done some of this.?

• I put in an ammeter in line with power, and as the rig powers up, it gets to just over 0.5A draw before it shuts off.? As I understand it, the op-amp circuit near the power connector uses the common mode choke as a current sense device and sends a "power off" signal to the CPU to shut things down if it doesn't like what it sees.

• I did unsolder the finals power lead, and removed the two-pin connectors to the drivers, with no help --- thought for sure that would be it.
• I have both fuses on mine, despite what the service manual says -- both check fine.
• I confirmed each of the power rails (5, 6, 9, and 13V) as the rig tries to power up, on the main board and the front display board, but I will look again at the test points you mention.

The service manual is pretty good at describing the RX and TX chains, but there is very little on power-up, reset, and shut-down conditions for the CPU and radio in general --? a common issue with Yaesu service manuals.? Wish there more voltages noted in the schematics.

b

On Sat, Oct 22, 2022 at 09:23 AM, Bill W1PA wrote:

If the finals are shorted, will the 817 not power up?

The finals are straight across the 13.8US (power unswitched), so they might well drag the supply down.
If the controller decides the voltage is too low, it will immediately power down.

The main power switching (for 5V,6V,9V) is done by Q1104 . I have had this fail. It failed high resistance, (i.e. there was some voltage, just not 12V)
From memory, the rig will power off immediately when this fails to switch on - probably because the main 5V will be low.
You can probe the switched 12V - TP1084 at the emitter of Q1082 - the big transistor by the 3x13VUS pins down to the PA, and the microphone socket. (block D2 on layout)

You can disconnect the the PA drivers with two jumper links on the transmit board next to the PA module.
There is a bare wire that connects the 13.8US to the PA module (finals) that you can lift to disconnect the finals.

It might be a good idea to do this while you play around getting the rest to run.
You should definitely not play around using batteries, best to use a variable supply set to 0.5A current limit.

On my version (-ND) there is a fuse for the 13V right before it goes down the 3 pins to the transmit board , (and another fuse for the battery). In the service manual diagrams, I don't see this fuse. (Perhaps that is part of the reason early ones destroy the transistors.)

In an attempt to clean drawers I have this stuff for sale:

- Yaesu YF-122S original filter (SSB). Like new, w/box. 120€
- New Inrad 500hz filter boards (no filter) for DIY'ers. Easy way is soldering
a 526-8693-010 Collins filter which are available on ebay or similar sites
at various prices, or you can build your own. 2 units, 30€ each.

Items are located in Spain, I'd prefer domestic or EU but will ship anywhere at
actual shipping costs.

Will listen sensible offers.

TIA


--
An expert is a person who has made all the mistakes that can be made in a very narrow field.
--- Niels Bohr