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Philly Uniden Grant XL-Hamfest Score!

Robb

Robb

Honorary Member Silent Key
Dec 18, 2008
11,432
3,653
323
Silicon Valley CA, Storm Lake IA
I went to the De Anza College Hamfest in Cupertino CA this morning, and SCORED a Philippine-made Grant XL for $10!

After jumping one of the choke coils in the 'power in' circuit (from the power plug to the main board) and cutting D55 (actually - it was already cracked. 1N4003 is used to replace it?), I got the thing to light up. It works very well on AM and SSB - both on RX and TX.

But what I need is a link to give this thing a proper tune-up. I know some of the VR adjustments are the same as a Cobra 148GTL; but I need to get the info on tuning up the receive, the reference oscillator, etc, etc.....
Anyone know of a decent link or know where this info may be found?

Thanks in advance!
(y)
 
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nice score rob!

the board may be laid out just a bit differently, but the alignment procedure for the 148GTL will work just fine.

i have a madison at home and it is the base version of the grant XL.
there are a few tuning cans in slightly different places, and i think the grant uses a variable cap instead of a tuning can for one of the IF adjustments, but all the values in the alignment procedure as far as voltage and frequency should hold true.

if it doesnt seem to be working for you for some reason or another, let me know and i will try to find my SAMS book for the madison.

good luck,
LC
 
From the Defpom site:
http://www.radiomods.co.nz/grantxlalignment.html

Test Setup: Preset To: Adjustments: Notes:
Input of oscilloscope to antenna jack.
No signal input. Ch. 19, USB VR4 BALANCE Adjust for MINIMUM RF.

Insert DC current meter at TP8 (pull wire from pin next to VR7).
No signal input. Ch. 19, USB VR9 Driver BIAS, Adjust for 25mA.
Insert DC current meter at TP7 (pull wire from pin next to VR7).
No signal input. Ch. 19, USB VR8 Final BIAS, Adjust for 5OmA.
Input of RF Watt meter to antenna jack.
Inject a 1000Hz, 100mV signal at mic input.
Ch. 19, USB

Mike Gain Maximum
VR11 SSB POWER (ALC) Adjust for 11 watts.
Input of RF Watt meter to antenna jack.
No signal input. Ch. 19, AM VR10 AM POWER Adjust for 3.8 watts.
Input of RF Watt meter to antenna
jack. Ch. 19, AM

MOD/S/RF S/RF
VR6 TX PWR METER Adjust VR6 so that TX PWR meter agrees with RF Watt meter
TX, Dummy load and SWR matcher Ch. 19, AM
VR12 Adjust the external SWR matcher to give a SWR of 2:1 adjust VR12 to agree with external SWR reading on meter.
Input of frequency counter through a
47pF capacitor to TP20 (IC1 Pin 7). Ch. 19, AM Check for 10.240MHz.
Input of oscilloscope to TP2 (to the left of L22). Ch. 19, AM L21 Adjust for maximum.
Input of frequency counter to TP3 (between L19 and L47)
Ch. 19, USB

Clarifier Midrange
L59 Adjust for 34.3515MHz (New Zealand).

Adjust for 34.985 MHz (FCC).


Ch. 19, AM

Clarifier Midrange
L23 Adjust for 34.350 MHz (New Zealand)

Adjust for 34.9815MHz (FCC).

Ch. 19, LSB

Clarifier Midrange
L22 Adjust for 34.3485MHz (New Zealand).

Adjust for 34.9885MHz (FCC).

Input of DC meter to TP1. Ch. 40, AM

Clarifier Midrange
L19 Adjust for 3.6 volts.
Input of oscilloscope to TP3. Ch. 19, AM

Clarifier Midrange
L20 Adjust for maximum.
Input of frequency counter to TP2 Ch. 1, AM Check for .790MHz.

Check all channels, it should increase by 10KHz per channel.

Input of frequency counter to TP5 (at back near Q19). Ch. 19, USB CT2 Adjust for 7.8015MHz +5Hz, -0Hz.
Ch. 19, LSB L30 Adjust for 7.7985MHz +0Hz, -5Hz.
Ch. 19, AM, Transmit L31 Disconnect TP7 and TP8.
Adjust for 7.8000MHz +5Hz.
Reconnect TP7 and TP8.

Input of frequency counter to R20(Q9 Emitter, next to X1). Ch. 19, AM Check for 7.345MHz.
Input of frequency counter to
antenna jack. Ch. 19, AM, Transmit VR5 Adjust for 26.550MHz (New Zealand).

Adjust for 27.185MHz (FCC)....
___________________
The Defpom page had a lot of the info I needed.
The t o u g h part right now - is locating the test points.
 
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In my experience, the clarifier mod is great.


Don't expect too much on a power meter, they just don't do much, but what it will do is quality.

Until you exceed the limits.
 
This radio -when I got it- already had the clarifier unlocked. I must say, that the SSB on it works very nice. The clarifier can move a great deal of hz. It swings about 20 watts on SSB.

The ANL/NB switch has been converted to additional frequencies. I don't know which ones yet, and I haven't used them either. The DIM/BRT and the HI/LOW switches have been disabled, apparently to put in a 10kc up/down. Maybe I will finish that part of it.

Cosmetically, the front bezel needs to be replaced. Other than that, the screws have a bit of rust on them. I've replaced about a dozen of them so far, an will also replace the rest of the external screws. It cleaned up all right, just need to get a full tune-up and a little TLC. It's a keeper; but some of the guys I talk to want to buy it.

I need to know if I should be looking for the sevice manual for the Madison or the 148 to get it dialed in? One thing is for sure, it is time for me to break down and buy a freq counter - like this one:
Protek 2GHz Frequency Counter (PROTEK U2000A)

Is the protection diode (D55) a 1N4003? Can I upgrade this to another 1N???? number?
Thanks in advance - again!
 
yes, D55 is a 1N4003. i wouldnt replace it with a higher current handling part because of the risk of burning something else up.

i bought two used freq counters before i realized that there's no point in having one unless you know its accurate. LOL then i finally bought a new one.
the one you are looking at looks good for the price.

the service manual (or SAMS photofact) for the madison will do you the most good if you have to troubleshoot things and also for locating parts on the board.

for just the alignment, the 148gtl procedure will work just fine.


i have a bunch of mods for this chassis if you are interested.

fast/slow AGC switch, wider TX audio response, faster AMC attack time, etc...

let me know if you are interested. you may already have them.

later,
LC
 
Are all of the tuning cans marked the same as the 148?
I know that I'm having a hard time with the test point locations.
I'd be interested the the TX mod for better audio response.
Also, the TR locations where I can put the Sanyo 2SC2999'e' for better recieve on AM and SSB may be nice to have. If it is at the same location as the 148, then I have that info. Since two of the switches don't do anything, I'm going to make one a 10kc switch; maybe I can make the other an AGC switch...
WHat would be the effect of using the more preferred 1N4004 over the 1N4003? Same 1 amp rating; but the piv is 400v instead of 200v.

The Defpom page I posted is a great reference for tuning this Grant XL.
 
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the test points are labeled in some versions and are not in some other versions.


this is a file i created a while ago:


remove c207, change R206 to 35-39K (pretty sure this is to broadband the balanced modulator. this mod has been around since the secret cb days.
ive never done JUST this mod to a radio to see what its effects are)

remove TR47 (this stops the radio from muting when you change channels.
its a preference thing, but i like to be able to hear as i spin the dial)

Q41(AM regulator) probably 2sc1419, change it to a 2N6487 (handles more current)

C18, change to 680uf-1000uF 16volt or bigger (this part is too low a value from the factory. will stop mic squeal after modding if it happens. i do it to all my radios)

change C109 to a 4.7uF 16 volt cap (faster AMC attack time)

change C172 to 3300uf 50volt (main filter cap)

change C163 to 3pf (broadbands the TX mixer so power doesnt drop off on extra channels)

C41 to 3pF for the RX broadbanding.

change R114 to 10k for wider audio response(you can experiment
to see how much lower you can go) i use 10K.
put R131 on a SPST switch. (AM mod limiter)

take a 10uf 25volt electrolytic cap & solder across spst switch,
find C23 & run leads from + & - to same polarities of cap
soldered to switch, fast & slow AGC for SSB.

replace Q14 with a 2SC2999


take the Q14 you removed & use it in place of Q19(2SC945).
that will be a major upgrade to SSB detector.

for even more increased AM sensitivity(& less noise)
replace D1, D2, D21, & D22 with 1N6263 schottky diodes

remove R95 to broadband VCO.



remove C174 (which is right in front of TR41)

get a 1000uF 16volt electrolytic capacitor, solder the negative lead to the negative hole of C174, and the positive lead to the leg of TR41 that is closest to the rear of the radio.

this is the "NPC" mod. there are a few different ways of doing it; i like this one.

VR7 is the AMC if you dont want to remove R131.

these are all mods i have done and can vouch for.

good luck,
LC
 
Yeah, time to buy a frequency counter - especially if you're going to start aligning SSB radios. There are a few tricks for getting it close without one, but you can't really do it right. I think you'll be real happy once you pick one up.
 
Well, I did that today. I ordered a freq counter today, and a can of 'Nutrol'. I needed both of them. I have so many radios that need the freq counter for a decent tune-up and most of these radios need a decent pot cleaning - including the Grant. The only thing I need for the freq counter is a test probe. Any $$$ saving suggestions for that part?

I didn't buy the 2ghz counter; I bought the 1ghz counter instead:
http://webtronics.stores.yahoo.net/pr1gfrco9.html
And the Nutrol:
http://webtronics.stores.yahoo.net/401b-340g.html

BTW BootyMon - I got the Nutrol because that is the most popular one.
I hope that was a decent choice too.
 
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the test probe i use for my freq counter is just a shielded cable with a BNC on one end and two clips on the other end.

i used to use a piece of coax cable with a BNC on one end and it seemed to work just fine.

this one would work just fine for you.

BNC TEST PROBE FOR ANY FUNCTION AND SIGNAL GENERATOR - eBay (item 380147063229 end time Sep-06-09 13:08:16 PDT)

i have had trouble in the past obtaining a sufficient signal from the 7.8mhz IF in this chassis, and have had to hunt around the TP for a suitable signal.
seems like this only happens to me with an MB8719 chassis.
maybe its just my freq counter, who knows.

you will have lots of fun with that new counter. i know it made a big difference in my attempts to align radios.
LC
 
the only thing I did not like about the protek was the resolution.

10Hz when going over 10 MHz range...

But it is a decent counter anyway.
 

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