email N4TZE@TWC.COM

 

LAST UPDATED 9/11/2006 with EPROM and Theory Of Operation Instructions from Manual at the bottom of this page.

I WILL NOT ACCEPT ANY RESPONSIBILITIES WITH THE ADJUSTMENTS DESCRIBED BELOW....YOU ARE ON YOUR OWN!

The adjustments shown here are for a Midland 70-050C Low band radio. I will not show the process to adjust the VCO's. The reason is that if you are not well versed in the VCO adjustment process, then you will destroy the radio. The VCO's MUST be measured at the original operating frequency. If this is not done then you will never get the radio to function in the 6 meter amateur radio band. If you want to attempt the VCO adjustment, or to get 75 watts out of the radio instead of the 40 after the modifications.....email me. You must be able to program the radio with the right software and/or program the 2716 chip without removing the 2716 chip.

The only thing that is most critical is that the radio works on the original freq and BEFORE you change the prom. Also BEFORE you change the prom (aka freq) you MUST measure the VCO voltage. After you change the prom/freq then make sure the VCO voltage is tweaked back to the original voltage setting. Meaning that at TP101 xmit VCO should be +6.78 vdc unkeyed and should be +4.33 vdc with the radio keyed. TP 701 rcv vco voltage should be +4.46 vdc unkeyed and +3.59 vdc keyed. You want to adj. the rcv vco first and the xmit vco second. Unit will do 75 watts max. Oh, by the way.the proms I use have to be erased then burned. If you are not familar with that process or how the data is on the prom then get someone else to do it for you. NOTE: ALWAYS SAVE THE ORIGINAL PROM DATA for troubleshooting the radio later or if you screw up so bad you need to start over. You will need to buy or obtain the pc software disk to load on your PC. That is how you make a prom image. Then take that data file and put it in your prom burner. Depending on your prom burner, you may have to shift the data file so all the data bits are in the correct places. That is why you save the original prom data file to compare it to. That's how I do it.

As always, you are on your own.

Good Luck.

N4TZE.

 

                                                                                   Overall view with the top cover removed.

  

The "Other" Top Cover Adjustments.

   

 

 

                                                                                    Overall view with the Bottom cover removed.

The "Other" Bottom Cover Adjustment.