Collins 32V3 RF Unit

[xe1yzy]

Guys

The RF Unit of my 32V3 needs to be refurbished at once, it is not an easy task due to the amount of components and rotary switches inside,but I have an extra RF Unit ,and I would like to try another circuit desing,  change the 7C5's for a more modern and compact tube ( sorry for the CC guys, but this modification is easy to be reversed).

Does anybody do this modification before? or someone have an Idea, tip or blessings for me  ?

Best regards and happy hollidays to all

XE1YZY

[Tom WA3KLR]

Feliz navidad Pedro,

The 7C5 is the loktal version of the 6V6. 
The 32V rf deck is a pain to work on.   
You can buy a 7C5 at Antique Electronic Supply of Arizona for US$7.16 each this  month.
It hardly seems worth the modification effort. 

Life is short, enjoy.

[N3DRB The Derb]

32 - V transmitters are all a PITA to repair.

[N2DTS]

My 32v3 has the same tubes in the rf section since I got it 30 years ago, they still work fine.
I had three 32v3's and never had a tube failure, or any other failure for that matter, and I solid stated the rectifiers (all of them) and have run it at 900 volts!

The only thing I would do is change the audio tube lineup, which is easy as stink in the 32v series rigs.
I use a pair of KT90 hifi tubes driven by a phaze inverter setup, the KT90's take no driving power in ab1...

I used to use it as an RF exciter for the big rigs, and I still use it from time to time, its had lots of use, with zero problems. Its one of two I got for $90.00.
The pto seems to be 5kc off, but I never looked into that..

There is no good reason to do anything with the 7c5's.

Brett



 

[xe1yzy]

Feliz Navidad to you too guys, thanks for your comments, well, looks there is no way out on this, I have to replace all the decoupling caps, carbon resistors, and some other trouble makers parts, my idea was have a more "space conserving" circuit desing. but looks is not an easy task, or at least an easy way to do it...

Yup, is a PITA work, but I prefer refurbished all unit and not have to get back for another failure

after all is a Collins rig isn't?

Best Regards

Pedro XE1YZY

[Steve - WB3HUZ]

Easy audio mods at the link below. No tube changes required.

http://www.amwindow.org/tech/htm/32v.htm

[KL7OF]

Easy audio mods at the link below. No tube changes required.

http://www.amwindow.org/tech/htm/32v.htm

I did these mods to my 32v1 and they work very well....I had to make some adjustments to the values of the cap and resistor on the feedback loop to keep the audio from FMing