[ARC5] Dynamotors and receivers

[Brian Clarke]

Hello Ken,

As the DM-34 is not the standard dynamotor for the Command series of 
receivers, of course you had to jury-rig it to your R-25. But, in the 
process you have converted what would normally be a very short, low 
inductance and low resistance connection between the ground of the receiver 
and the frame of the dynamotor into a transmitting antenna. I suspect that 
had you had a DM-32 base onto which to mount your DM-34, you would not have 
heard the crackling. It is also possible the capacitors across the primary 
and secondary brushes may not be connected properly - or have failed.

How do you get 40 and 20 on a R-25 Rx? [(:-,)]

73 de Brian, VK2GCE.

On Sunday, June 09, 2013 3:17 PM, you said:


> Tonight, I tested an R-25 receiver I have been working on here by powering
> it with a DM-34 dynamotor. I first cleaned then greased the dynamotor's
> bearings with that grease that Mike Hanz recommended.
>
> I was using clip-leads to connect everything together with. At first, 
> there was
> some minor "crackling" noticeable in the audio, but when I connected the
> frame of the dynamotor to the chassis of the receiver with another 
> clip-lead,
> the crackling disappeared.
>
> Innersting....
>
> Boy! Band conditions are just awful. Very few signals on any band but 40
> and 20.
>
> Ken W7EKB