Saturday, January 2, 2021

GDO AN PRM10

GDO AN PRM10 Recently my friend gave me his AN PRM10 grid dip oscillator. Well, in days of micro SDR and softwre DDS VFO who plays with this WW2 age devices ? 

It was a nostalgia for me. Cost was a bitter stip but he made it light due to his affection for me by sending me extra 2,5 kg power transformer, 50 watt dummy load and a meter. There were other buyers but he wanted to sell to actual users. My friend inquired why i did not home-brew anything or not on air for quite some time ? we had big chit-chat about me, my lifes updowns, homebrewing etc. he lowered price for me.He is my generous benefactors over the years. Earlier he had gifted me some RF boards, SPART hard compy a years magazine set. I just grabbed this GDO. I could have bought the microBITX but now a days i am detesting everything slamic. So, i wait for the xtian & pure hindu brewers to get me things. Well, that is my spiritual issue and nothing can be said or done on that. Well will finish later on.

He posted me the device through the couriers. it took strong 10 days to reach me. Then i did a first test of power on and blew the fuse. Then i reverted to him with my problem and tried to make my transformer using the reverse transformer idea but as the loading was pure resistivity, it required the current and voltage. So, once again i requested to send the transformer (as free fund). Very kind of him. its a bit heavy 2.5 kg piece. he specially found out from some radio junk. It was very dusty. dusted it used it. 

Then did the first test. with this new power supply. it dipped only 14 Mhz coils. i was thinking that other coils are 10 Mhz which it did not dip on 10-22 Mhz range nor in 5 to 10 Mhz range. Later on i ferefered my ckt diagram. Actually the If was a tunable 4 Mhz around. so, i said that it is success. hee hee. 

Then today did a oscillation check. injected the RF oscillations into the xtal controlled DC receiver. it produced good stable tone. Freq was very stable. good enough. the stray metal capacitance was not affecting the internal device. so that was the thing if you make a gdo it should be air tight. ok later one. 

on my you-tube channel there are videos. just google AN PRM10 and my videos come up on search. There are not many of these equipment surviving. I do not know whether how it dips or not as never used this type of instruments. thus test is going on, as i have to master this equipment. 

Yes, the equipment works but i will take time to learn.

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