HG -10,Eico 720, SC-40B

2006/05/03
 
HG-10, EICO 720, SC-40B
 
I was using Heathkit HG-10 VFO feeding the signal into Eico 720 transmitter and receiving the signal with Hallicrafters SC-40B for QRP QSO for about a month in the past.  These are tube rigs in 1950s and 1960s.
 
I built a power supply to run the HG-10 VFO.  I noticed the CW note was not clean and not stable(a bit chirpy and wabble) when I started using these rigs.  So I up-graded and modified the homebrew power supply unit on the rectifying section and the filtering section.
 
Rectifying:  I removed one single rectifying diode and installed a bridge rectifier to get full wave rectifying.
Filtering:     I removed a resistor on the electrolytic capacitors and installed a chock.
 
I checked the wave being genarated with my oscilloscope and saw a fairly straight line and noticed good improvement on running HG-10 and Eico 720 for the CW note, not chirpy and not wobble either.
 
Some of my QSOs after this improvement made since April 22, 2006 are:
KA0YSV, N3EF/QRP, K8ZCT, KF0UU/QRP, W4VAH, KB2AMY, WB2AMY, WB2NVS, N2WJW, K3CB/M, KA3CFC/QRP to date (May 3, 2006).
 
This entry was posted in ham radio. Bookmark the permalink.

3 Responses to HG -10,Eico 720, SC-40B

  1. Unknown says:

    Amberdigital Branch,Southern Stars Enterprises Co is specializing in the development and manufacturing of advertisement screens, LCD digital signage and LCD signages. Established in 1996, we have explored and developed the international market with professionalism. We have built a widespread marketing network, and set up a capable management team dedicated to provide beyond-expectation services to our customers.

    amberdigital Contact Us
    Southern Stars Enterprises Co (Hong Kong Office)
    Add:3 Fl, No.2, Lane 2, Kam Tsin Tsuen, Sheung Shui, Hong Kong
    Tel:+852 2681 4099
    Fax:+852 2681 4586
    Southern Stars Enterprises Co (Shenzhen Office)
    Add:DE, 16/F, Building 2, Nanguo Tower, Sungang Road, Shenzhen, China
    Tel:+86 755 2592 9100
    Fax:+86 755 2592 7171
    E-mail:sstar@netvigator.com
    website:www.amberdigital.com.hk
    alibaba:amberdigital.en.alibaba.com[dcafibdgbdiba]

  2. Unknown says:

    Hi,Do you have second hand lcds, used laptop lcds and used LCD displays? Please go here:www.sstar-hk.com(Southern Stars).We are constantly buying re-usable LCD panels.We recycled LCDs.The re-usable panels go through strictly designed process of categorizing, checking, testing, repairing and refurbishing before they are re-used to make remanufactured LCD displays and TV sets.Due to our recent breakthrough in testing and repairing technology of LCD, we can improve the value for your LCD panels.
    website:www.sstar-hk.com[gjcafbefbigaha]

  3. Unknown says:

    Hi,Do you need digital signages, advertising displays, digital sign, advertisement displays and advertising players? Please go Here:www.amberdigital.com.hk(Amberdigital).we have explored and developed the international market with professionalism. We have built a widespread marketing network, and set up a capable management team dedicated to provide beyond-expectation services to our customers.
    amberdigital Contact Us
    website:www.amberdigital.com.hk
    alibaba:amberdigital.en.alibaba.com[acbf

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s