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Expo 100 channel kit Or Modify PLL and switches?

jtrouter

Active Member
Jul 7, 2015
95
36
28
62
Hello to all the big brains out here:)
I have read on this forum that the expo kits are fine for AM but not the
best for ssb. So is it a safe assumption that on a Cobra 2000 its a better choice
to do the PLL trick with the switches. And if i use the switches I WILL NOT hack
up the front or back of the radio. I personally do not like to see these radios hacked
up, There are ways to add things with drilling. Thank you.
 
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9C1Driver

Sr. Member
Aug 13, 2008
3,649
1,559
173
On a Cobra 2000 I would just have the mod done off the PLL with a single 3 way rotary switch. I had that done on my Uniden Madison with the 8719 PLL and it works great. Many years ago I had an expo kit done to a Uniden Grant xl and it worked fine but the radio was not as stable on SSB that I would have liked.
 

nomadradio

Analog Retentive
Apr 3, 2005
5,297
7,597
573
Louisville, KY
www.nomadradio.com
Over the years, I have advised a customer who only cares about AM that the Expo kit is easier to use, since it's a true band selector. Both new sets of 40 channels are all in a nice, sensible row.

But the drawback is stability. The frequency will drift more with the Expo kit, but not enough to cause any practical issue for operating AM.

Sideband is another matter. If the customer fancied stable SSB performance, I would recommend using the 8719 chip to add channels. The 11.325 MHz factory crystal will be more stable than the Expo hookup.

Drawback is that the order of the new channels is a bit scrambled up. OTOH, a radio with a frequency counter display makes up for that a lot. Just look at the display to find out where you are. The "chart" that showed which new frequency is where would be your only hope to find a channel without a counter display.

As with a lot of technical choices, it depends on your priorities.

73
 
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jtrouter

Active Member
Jul 7, 2015
95
36
28
62
As always thank you for confirming what i thought i had read before. I do use
AM more than Ssb, but i do use it enough that i would not want to make it less
stable. And funny that you mention DDS i was visiting a friend yesterday and they
had a radio with a remote DDS Vfo and it was super slick and the first time that i had seen and used one in person. What a great time to to be playing in radio.
 
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Fragle

New Member
Jan 17, 2022
3
1
3
56
I put a Digimax in my 2000 and like it.The Radio looks original,no crazy switches,its stable,goes from 26 something - 29 something with 5 kz steps and scan funktion.To me the best mod for my Radio.Hope to find somebody with a FM Maurer board next.
 
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johnnytek

New Member
Sep 5, 2021
24
8
3
82
Hello to all the big brains out here:)
I have read on this forum that the expo kits are fine for AM but not the
best for ssb. So is it a safe assumption that on a Cobra 2000 its a better choice
to do the PLL trick with the switches. And if i use the switches I WILL NOT hack
up the front or back of the radio. I personally do not like to see these radios hacked
up, There are ways to add things with drilling. Thank you.
i always use a xtal and put it on a relay next to the original socket with the shortest leads and with a 5-50pf trimmer. switch it with a (installed 8 volt regulator and relay-on a switch.
 

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