IC 718 and Transverters

[VK4KL]

As anyone successfully used a 6 meter transverter with an IC 718?
I have a Mutek 6 meter transverter

Adrian

[VK3DXE]

I really don't know that I'd bother. I once modified a Yaesu FT747 to work with the Yaesu transverters and it worked OK, but I think you're wasting your time on what is a relatively low-end rig.

[VK4KL]

We can't all afford wiz bang radios so I have to make do with a cheap radio but would still like to try 6 meters.

Adrian

[VK3DXE]

We can't all afford wiz bang radios so I have to make do with a cheap radio but would still like to try 6 meters.

Adrian

OK, sorry I didn't mean to come across negatively.

You would have to see what's the lowest power output you can get from the 718, then possibly attenuate it down to whatever the transverter requires. The 718 should have a TX switching output on one of the ACC sockets. At the very least, you could use it as a receive converter to at least listen to what's happening on the band.

[VK4TJ]

If you can get a schematic for the Ten-Tec 1208, you could probably use a similar method. The TenTecs work with 5 watts, a largeish attenuator, and diode swithing between Rx and Tx.
The downside is, of course, that if you ever forget, and hit it with the full 100 watts, bye-bye attenuator, bye bye Mutek.

I once did an IC-726 transverter mod - routed the cable from the low level RF board to the back panel instead of directly to the PA deck. The IC-718 is no doubt similar. Look out- though - if the PA board ever sees an open input, it makes a magnificent free-running 100 watt oscillator. I don't recommend this!

The irony of it all is that most of these "high first IF" rigs, which the 718 is almost certainly one of, could generate a low-level 6 mtr signal natively with a software change and minor design changes to the PLL.

[VK4GHZ]

As anyone successfully used a 6 meter transverter with an IC 718?
I have a Mutek 6 meter transverter

Adrian (and others!),
When set to "low" power (2W according to the brochure), does the IC-718 have any overshoot problems that the IC-706 is famous for?
Any brief high powered spike could damage your transverter system.
(This is why the QRP Yaesu FT-817 has become such a popular IF transceiver for microwave systems - none of these problems to begin with.)

From a cursory glance I cannot see a visible RF power level pot on the IC-718 front panel.
Perhaps this is done within the Set menu?
Another cause of (certain!) failure would be to forget to adjust from 100W down to minimum in the "heat of the moment".

Unless you have an endless amount time (retired?) you might be better off saving up for a rig that 6m built in, and avoid any potential hassles.
These appear on the 2nd hand market regularly, and in all price ranges.

Don't want to put you off, but issues to be aware of, and try to avoid going down "false savings boulevard".

[VK4ADC]

Another option is to feed a negative voltage in on the ALC pin on the accessory socket, typically around the -4 to -5V mark and presettable from a potentiometer. Set the negative voltage to produce typically 1 to 2 watts RF out with the power setting (in the 718's setup screens) set to maximum (ie 100W).

If you derive the negative voltage from the transverter power line (eg using a +5V regulator into a ICL7660 -ve generator to create the -5V) then the ALC immediately gets it's RF power setting voltage supplied as soon as the transverter is powered up, and stays there in both transmit and receive modes.

I've done it with my 718 to run a homebrew 70cm transverter in earlier times and it worked well for me....

[VK4KL]

Thanks Doug I will look into this

Adrian

Have just ordered the 13 pin DIN and the IC7660 to do the job

[VK4ADC]

using a +5V regulator into a ICL7660 -ve generator to create the -5V

The 7660's cannot take 12V (nominal) and you will need to run it from a 5V positive regulator rather than direct.

[VK4KL]

The 7660's cannot take 12V (nominal) and you will need to run it from a 5V positive regulator rather than direct.

No problem I have already setup +5v in the transverter in readiness

Adrian

[VK4KL]

Old thread I know but I put the Mutek into storage again and bought a Kenwood TS480SAT instead.

Adrian

[VK3ZAZ]

Hi
I have used transverters right back to the boonie times
The most recent was a FT1000MP and very expensive TV1000
My opinion waste of time
lots of reasons especially 28 MHZ feed thru and lack of calibration,
Best was 1000MP as you could set the pre freq to 50

Second issue must disable the high power and find a low power input source
And with the s/s of 28 MHz you will get feed through and think you are hearing a 6M station when it will be a 10M station .
so I you look back through old ARRL and RSGB you will find what you need.
The rig specifics not insurmountable providing you have set it up right.

As for whiz bang rigs a used 706 or TS680S or even ts660 not expensive and work really well.



good luck