The AM Forum

THE AM BULLETIN BOARD => Technical Forum => Topic started by: aa5wg on May 25, 2010, 01:11:01 AM



Title: Drake R7 and T4X-C
Post by: aa5wg on May 25, 2010, 01:11:01 AM
Hi to all:
Can the Drake R7 receiver be used with the Drake T-4XC transmitter?
73,
Chuck - AA5WG


Title: Re: Drake R7 and T4X-C
Post by: Pete, WA2CWA on May 25, 2010, 02:11:06 AM
Absolutely. Most receivers and transmitters, as long as they cover the same frequency ranges, are not dependent on each other.


Title: Re: Drake R7 and T4X-C
Post by: SA7AUY on May 25, 2010, 02:24:32 AM
It should be possible. I have attached two pictures from the R7A and the T4X-C manuals.

/ SA7AUY


Title: Re: Drake R7 and T4X-C
Post by: WQ9E on May 25, 2010, 09:31:43 AM
Chuck,

They can be used together but not like pairing the R-4C receiver with the transmitter.  They will work fine as separates but the R-7 won't control the transmitter frequency in transceive mode.

The R-7 is a great receiver (I have one paired with a TR-7A) but finding an R-4C (or an even an earlier R-4B, R-4A, or R-4) will make a better setup for the T-4XC.


Title: Re: Drake R7 and T4X-C
Post by: WA1GFZ on May 25, 2010, 12:42:09 PM
I think the R7 it triple conversion but the TR7 RX is dual conversion.


Title: Re: Drake R7 and T4X-C
Post by: aa5wg on May 25, 2010, 01:02:36 PM
Hello WA1GFZ, WQ9E, SA7AUY, WA2CWA and all:
Thank you for your help with the Drake chanllenge.  I think what  I need is a late serial number Drake R4C to have true transceive.  At present, my preference would be the R4C rather than the B-ine, A-Line or straight R4. 
73,
Chuck - AA5WG


Title: Re: Drake R7 and T4X-C
Post by: WQ9E on May 25, 2010, 05:44:22 PM
The R-4C is the best match and the later models have 5 filter positions.   It will receive AM with just a resistor across the AM specific filter slot and the bandwidth is set by the 1'st IF filter which has very wide skirts.  The various original (Network Science) filters show up on ebay fairly often as do the Sherwood narrow CW filters; otherwise Inrad can supply you with modern versions.  If it doesn't come with the noise blanker, be prepared to pay a lot if you want one.  A number of high performance modifications are available.

The R-4B will do a fine job also with its L/C filters but it doesn't quite match cosmetically.  It also is missing the port to sync the BFO/carrier oscillator between the units so you have to adjust manually if you cross match the C with an earlier version.



Title: Re: Drake R7 and T4X-C
Post by: aa5wg on May 25, 2010, 08:15:14 PM
WQ9E:
Thank you for your info.  I  will look for a Drake R-4C.  I head there was a rf amp., 1st mixer, 2nd mixer and 3rd mixer modifications for this nice receiver.  Is this true?   And, if so where can I read up on these modications?
Thank you.
73,
Chuck - AA5WG


Title: Re: Drake R7 and T4X-C
Post by: WQ9E on May 25, 2010, 09:01:31 PM
A couple of good starting points are: 

http://www.zerobeat.net/drakelist/drakemod/drmodtoc.html  (information about different Drake products but mostly 4 line)

and  http://www.sherweng.com/ham.html

Even without modification, a properly performing R-4C is a very good receiver.  One of mine is bone stock, the other has Sherwood roofing and narrow CW filters along with updated audio amp and power supply.  I haven't done anything to the mixers in mine.  The R-4C with Sherwood filters and an Autek QF-1A (outboard audio filter) is substantially better than my Yaesu 1000MP with its Inrad filters and DSP for CW DXing on 160 and 80.


Title: Re: Drake R7 and T4X-C
Post by: aa5wg on June 09, 2010, 10:31:53 PM
WQ9E: Thank you.
Chuck
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands