[Motorola] More Motorola ConvertaCom Q's

[John Jewkes W6HNC/AAR0MI]

Motorola is adept at hiding the screws to things, generally behind 
rubber plugs and such. In most cases, the adapters (Other than the 
actual ones made by motorola directly) tend to have a solid core and do 
not work well on VHF and UHF frequencies, as they try to resonate, 
causing RF feedback and heat load which the finals logic circuit to 
reduce output power to close to zero. Larsen-Radiall makes most of it's 
antenna/coax assemblies with the mini-uhf as well as the PL-259. I find 
it very rare, only 1 in 100 I've owned and fixed for others had a bad 
connector on it's backside. 3 others had bad RF Transistors. I assume 
you already know that you need to make sure the HT you put into the 
convert-a-com is the correct model for the unit, and in the right 
frequency range. That is the most common error I've seen is hooking a 
UHF HT into a VHF Converta-com (Read Amplifier mismatch). UHF won't pass 
through a VHF amplifier and vice-versa.
The Frequency range is coded into the model number of the unit, just 
like on the radios. I know that someone on the list actually has the 
position and 'identifier' info, as I no longer have a copy of the chart.
But for example the number 1 might be VHF lower segment (136 to 151)and 
2 might be VHF higher segment (155 to 174).
73 de John Jewkes W6HNC.

Dennis Wade wrote on 3/5/2006, 11:00 AM:

 > Thanks all for the replies to my questions about the ConvertaCom.
 >
 > >From those replies, I am thinking I either have a defective mini-uhf
 > female on the back panel, or a substandard mini-UHF adapter (or both I
 > suppose).
 >
 > I'd like to change out that rear panel to a BNC (might be room).
 > Anybody do this?
 >
 > How do I get into the thing...didn't see any obvious way.
 >
 > Thanks,
 >
 >        Dennis
 >
 > --
 > Dennis L. Wade
 > KG6ZI
 > Carmichael, CA
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