Acquired a Vocom Products 500 watt UHF amp

[Moleculo]

I was recently discussing with a friend the need for a high power UHF amp for a special project. To my surprise, he said that he had a 500 watt Vocom UHF amp tuned for the ham band sitting in his storage shed that he hasn't used in years. A week later, it was in my hands.

While not heavy this thing is huge. I couldn't find a model number; it only has an FCC ID that doesn't seem valid. So, I decided to pop it open and see what's under the covers.

As you can see, it has two RF decks, individually powered. The transistor PA arrangement appears to be 1 MRF646 driving 4 MRF646's driving 8 MRF658's.

I looked up the specs on these datasheets, and I have a feeling this amp may be capable of putting out more than 500 watts. I need to order a Bird 43 slug capable of handling this much power and a power supply. I hope it works...stay tuned!

 

[SuperLid]

I was recently discussing with a friend the need for a high power UHF amp for a special project. To my surprise, he said that he had a 500 watt Vocom UHF amp tuned for the ham band sitting in his storage shed that he hasn't used in years. A week later, it was in my hands.
View attachment 70170

While not heavy this thing is huge. I couldn't find a model number; it only has an FCC ID that doesn't seem valid. So, I decided to pop it open and see what's under the covers.

View attachment 70172

As you can see, it has two RF decks, individually powered. The transistor PA arrangement appears to be 1 MRF646 driving 4 MRF646's driving 8 MRF658's.

I looked up the specs on these datasheets, and I have a feeling this amp may be capable of putting out more than 500 watts. I need to order a Bird 43 slug capable of handling this much power and a power supply. I hope it works...stay tuned!

It should be around 500 W. I think it may need to be repaired from the looks of some of the balancing resistors. I knew the owner of that company, as I was a VoCom dealer in the 80's. He was from the Schaumburg IL area, worked for Mot at one point. I can't remember his name though.

 

[Pioneer621]

It should be around 500 W. I think it may need to be repaired from the looks of some of the balancing resistors. I knew the owner of that company, as I was a VoCom dealer in the 80's. He was from the Schaumburg IL area, worked for Mot at one point. I can't remember his name though.

Yeah some of the resistors do look a bit discolored when you zoom in.


I remember getting a blown smaller gold color VoCom at a hamfest for a couple dollars like 15+ years ago. I built a small four IRF520 amp with it back then and ran it at 100w peak for the CB.