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Hi?
I was wondering if anyone has any tip on this combo

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it seems to work ok but as the 817 is so low power , the T/R switching on the amp keeps cutting in and out on ssb with the audio.. When Im at full voice its fine, but on pauses as i take a breath (yes I do that!) it? goes to RX again,, meaning every over is on/off/on/off and choppy. I need faster tx/attack... but longer "hang time" to stay in tx after i shut my pie-hole a few seconds.

Does anyone us has used this combo know if there is an adjuster in the amp or mod for this.??
Any thoughts?

73 de Jem
VK7JEM

Jem,

It sounds like you have VOX turned on.? It is found on the front panel menus.? Access by pressing the F key and use the select knob to move to menu 10 VOX.? Pressing the A key turns it on and off.

--

Al Skierkiewicz
WB9UVJ

Hi Jem,

If the rx tx switch is relay activated it may be possible to alter the switch time by using a different capacitor depending on the circuit.

I have a 70w amp for my 817 which has an electrolytic which feeds a transistor controlling the relay closure, opening is instant with 1w rf. Varying the value of the cap alters the close time of relay.

Andy

Looking at the schematic could vr201 alter the hang time?

Hi Jem,

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please download service manual to adjust delay time and RF sensing sensitivity .

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WARNING -
Just a word of warning when uses this amplifier with a FT-817. Used in the RF detection change over mode, this set-up lasted about 5 min before the '817 PA module blew!

I guess the change over time of the amplifier relay was enough to leave the '817 output unterminated, and with no effective high SWR protection in the 817, caused the PA to fail.

73,

Rob VK2MZ

Jem,

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So it is best to use a PTT keying line ?so when you press the microphone, the FT817 is in TX mode with red LED on, and the FL110 is in TX mode with red LED on and then you speak which then produced RF. ?The FT817 finals see a proper load.

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By using RF sensing, the FL110 is in receive mode, you speak and transmit RF to the amp which senses Rf, the slow changing relay in the amp switches from rx to tx, that slow changeover means for a small amount of time the FT 817 finals don’t see a proper load and can be destroyed.

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I have been using my FT817 and FL1110 for over 20 years with a direct PTT line without any final damage.

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73

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Rob VK2MZ

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Hi everyone
Some great? answers here that seem to have given me the info I need

Yes its the RF sense switching thats causing the issue - I much would rather use a ptt sensing myself.

As suggested , I will rig up a connection from the ptt pin on the data or acc port to pin 4 on the amp power connector.?
Due to a slight physical disability i find fine soldering an extreme challenge.. so working with those old din connectors is not a chore i look forward to. hihi!?
So, as I use an MD1 desk mic, it might be easier to tap onto the PTT line on its much bigger connector or inside the base itself?

Alternately, I could make a big? button connected to pin 4 on the amp that I manually hit? just before or after i press ptt each time, if i want high power this over.
Stick it on the mic base next to the PTT.


Great stuff all! Great bunch of hams we have using these brilliant tiny boxes
Hopefully we can have a 817 to 81x chat soon!

THanks for this?
73 de VK7JEM?

Closing the loop and following up. I went the route of opening the base of the mic and running a wire from the cct board to the FL110 Pin 4.
Simple job, works perfectly.?
The only thing i MUST remember is only turn the amp on when I am on HF!!!!!

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Hi,

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switching the FL-110 via the ptt line is drawing quite some current. If I remember it right, it is arround 100 mA.

To check, just put a amperemeter in line and ground the contact. This may be a bit much for the ptt out of the 817/818 and a buffer stage may be advised.

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73, Chris

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