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BITX V6 MAXIMUM INPUT REG


LAKSH MUTHU
 

Dear All,
     Good Day.
Kindly let me know what is the maximum input voltage that can be given to UBITX V6 without any modification.  Presently I am supplying 13.5 V to the rig. Current drawal is 1.5 amp at 40m and 1.2amp at 20m. Both values include idle current of 0.3 amp. This means current drawal in 40m and 20m in TX mode are 1.1amp and 0.9 amp respectively. I like to increase power input. So, what  safe maximum voltage can be supplied to UBITX V6.
 Regards
73
MUTHU
VU2LMN


 

On Fri, Sep 18, 2020 at 08:40 PM, LAKSH MUTHU wrote:
Dear All,
     Good Day.
Kindly let me know what is the maximum input voltage that can be given to UBITX V6 without any modification.  Presently I am supplying 13.5 V to the rig. Current drawal is 1.5 amp at 40m and 1.2amp at 20m. Both values include idle current of 0.3 amp. This means current drawal in 40m and 20m in TX mode are 1.1amp and 0.9 amp respectively. I like to increase power input. So, what  safe maximum voltage can be supplied to UBITX V6.
 Regards
73
MUTHU
VU2LMN
Hello Muthu,
the maximum power voltage is defined by one component : LM386N-1 that have MAX 14Vcc power supply (look the data-sheet at : https://www.ti.com/lit/ds/symlink/lm386.pdf?HQS=TI-null-null-mousermode-df-pf-null-wwe&ts=1600459750453 be careful, at 15,2 Vcc the LM386N-1 renders the soul ... hi. hi. hi ... this from my experience in other projects !

if you want to increase the power even more, i don't know if other components have limitations (e.g. power mos of the final amplifier), for the LM386 you could try to replace it with the model LM386N-4 (Mouser part n.926-LM386N-4 ) which can sustain about 18/20 Vdc power supply, but pay close attention to the other components !!!! it's not nice to see SMD components smoke !!!
 
Greetings .. 73 de IW4AJR Loris


Jerry Gaffke
 

You could separate out the 12v into the finals at L9, increase that voltage up to perhaps 20 volts
while keeping the rest of the rig at 12v. 

Jerry, KE7ER


On Fri, Sep 18, 2020 at 01:25 PM, IW4AJR Loris wrote:
On Fri, Sep 18, 2020 at 08:40 PM, LAKSH MUTHU wrote:
Dear All,
     Good Day.
Kindly let me know what is the maximum input voltage that can be given to UBITX V6 without any modification.  Presently I am supplying 13.5 V to the rig. Current drawal is 1.5 amp at 40m and 1.2amp at 20m. Both values include idle current of 0.3 amp. This means current drawal in 40m and 20m in TX mode are 1.1amp and 0.9 amp respectively. I like to increase power input. So, what  safe maximum voltage can be supplied to UBITX V6.
 Regards
73
MUTHU
VU2LMN
Hello Muthu,
the maximum power voltage is defined by one component : LM386N-1 that have MAX 14Vcc power supply (look the data-sheet at : https://www.ti.com/lit/ds/symlink/lm386.pdf?HQS=TI-null-null-mousermode-df-pf-null-wwe&ts=1600459750453 be careful, at 15,2 Vcc the LM386N-1 renders the soul ... hi. hi. hi ... this from my experience in other projects !

if you want to increase the power even more, i don't know if other components have limitations (e.g. power mos of the final amplifier), for the LM386 you could try to replace it with the model LM386N-4 (Mouser part n.926-LM386N-4 ) which can sustain about 18/20 Vdc power supply, but pay close attention to the other components !!!! it's not nice to see SMD components smoke !!!
 
Greetings .. 73 de IW4AJR Loris


 

Thank you Jerry, I didn't know the limit of the finals.


Jerry Gaffke
 

The IRF510's should have a better heat sink if you are asking for more power from them.
Tabs should never get uncomfortably hot to touch.
The silicon die in the IRF510's will be much hotter, as thermal conductivity from die to tab is not very good.

Many in this forum have successfully boosted power by increasing voltage to the finals.  
A few have destroyed their IRF510's.

Also, as more power goes out of the IRF510's, they demand more power from the previous stages.
This may result in distortion or spurious products.

Jerry, KE7ER


On Fri, Sep 18, 2020 at 02:13 PM, IW4AJR Loris wrote:
Thank you Jerry, I didn't know the limit of the finals.