Cobra 135 with a Siltronix VFO

[38Special]

Hi, I need a little help with my next project. I have a Cobra 135 base station with a D-104 base mic on it. I would like to put a VFO on it because it is a little off freq. on sideband on some channels. Siltronixs makes a nice old model 90. If I understand correctly they came in different dash numbers??? Do I need a specific dash number to work on a Cobra 135(A)? Is it a big deal hooking it up or does it need to be wired in? I'm pretty handy with wiring diagrams and a soldering iron.... Where can I go for answers?

[Rex_foxhound]

Welcome to the forum!!

I don't know the answer to your question but maybe somebody else will.

[BigBopper]

You need a Siltronix 90A (11.955MHz) if your serial#is below SER# 30,000,,,with above 30,000 serial# you need 90-7 (16.215), On some models you just plug them in the Channel Crystal spot, some guys used channel 23 and removed the crystal and plugged in the Siltronix VFO,,,,the drift until they warm up...hope that helps some

[38Special]

I'm bidding on one right now on ebay.... It's a model 90, and I sent out a message to the owner to look for a dash number, asked if there was any wiring or manuals that went along with it. It seems like the "perfect" retro mod for my old cobra 135. If it doesn't have any wiring then what? Am I screwed or is that something I can sort out later. Manuals are available. Anybody in Virginia out the on this board that likes tinkering with this stuff???? Thanks for the warm welcome to the board!!!! I hope you guys can steer me in the right direction with all this vintage equipment! TJ

[38Special]

I just took a look again at the 2 vfo's on ebay. The vfo I'm bidding on appears to be a 1 (has a number on the back on the right side in black ink) The other vfo on ebay is a 5, it has it's number on the back on the right side as well (I looked at this one first as it's listed as a #5 to see where the number was located). Will the 1 work for me? I'm certain my cobra 135 is a model A but will double check the serial number tomorrow night. TJ
(please don't overbid me!)

[BigBopper]

if your serial# is below 30,000, you'll need a 90-1, but Siltronix made 3 different 90-1"s, (11.950MHz,,11.955MHz,,11.990MHz),,,and you'll need 11.955,,,if you get the wrong one it won't work, manuals can be bought on eBay and the internet,,,,the VFo on eBay you'll need what model 1 it is, remember they made 3 models

[38Special]

The serial number on the unit is 014301. I don't suppose there is any way of linking the serial number to the model 90-1 to figure out what it is? The seller is not responding to questions being asked, so I take it they don't know. I suspect it is probably a woman as they are selling numerous clothing items and this VFO seems to be an oddball item. Just my luck

[BigBopper]

if your serial# is below 30,000, you'll need a 90-1, but Siltronix made 3 different 90-1"s, (11.950MHz,,11.955MHz,,11.990MHz),,,and you'll need 11.955,,,if you get the wrong one it won't work, manuals can be bought on eBay and the internet,,,,the VFo on eBay you'll need what model 1 it is, remember they made 3 models

The only one that will work will be 11.955mhz

[38Special]

It's not something that can be selected (pinned) inside the -1 box? I am unfamiliar with these boxes (can you tell?) TJ
My serial number on my 135 is 64-06341. I need the -7 correct?

[38Special]

The seller claims that there are no other numbers anywhere on the VFO, and that the dial goes from frequency 26.925 to 27.830. Is there someone I could contact who would know a little something about these units??? TJ

[North Texas Mudduck]

the siltronix i have is a model 80
goes from 26.925 to i think 27.850

[jug head]

I have one new in the box if you are still looking for one. I have the installation and user in with it. It states on the install guide it is for New Cobra 135, serial numbers r-30,000 and higher. Let me know if that is what you need